移动应用开发技术实验代码

实验二

实验2.1

main_activity.java

package com.example.text2;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.RadioGroup;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private EditText name = null;
    private Button tixing = null;
    private CheckBox box1 , box2 , box3, box4;

    private List<CheckBox> checkBoxList = new ArrayList<CheckBox>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        this.name = (EditText)super.findViewById(R.id.edit1);
        this.tixing = (Button)super.findViewById((R.id.tixing));
        box1 = (CheckBox)super.findViewById((R.id.box1));
        box2 = (CheckBox)super.findViewById((R.id.box2));
        box3 = (CheckBox)super.findViewById((R.id.box3));
        box4 = (CheckBox)super.findViewById((R.id.box4));

        checkBoxList.add(box1);
        checkBoxList.add(box2);
        checkBoxList.add(box3);
        checkBoxList.add(box4);

        tixing.setOnClickListener(new ShowListerer());

    }
    private class ShowListerer implements View.OnClickListener {
        public void onClick(View v)
        {
            StringBuffer sb = new StringBuffer();
            for (CheckBox checkbox : checkBoxList) {
                if (checkbox.isChecked()){
                    sb.append(checkbox.getText().toString() + " ");
                }
            }
            String info = name.getText().toString();
            AlertDialog.Builder builder= new AlertDialog.Builder(MainActivity.this);//MainActivity.this为当前环境



            if(info.trim().equals(""))
            {
                builder.setMessage("请输入姓名");//提示内容
            }
            else
            {
                builder.setMessage("姓名是: "+info+"\n"+"性别"+"\n"+"专业"+"\n"+"兴趣爱好 "+""+sb.toString());//提示内容

            }

            builder.setPositiveButton("确认", null);//确定按钮

            builder.create().show();

        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="left"
        android:layout_marginLeft="10dp"
        android:orientation="horizontal">
        <TextView
            android:id="@+id/name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="姓名:"
            android:textSize="20dp"
            android:layout_weight="1"/>

        <EditText
            android:id="@+id/edit1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="李坤松 2012020047"
            android:textSize="20dp"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="left"
        android:orientation="horizontal">
        <TextView
            android:id="@+id/gender"
            android:layout_marginLeft="10dp"
            android:layout_marginTop="19dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="性别"
            android:textSize="20dp" />
        <RadioGroup
            android:id="@+id/Radio1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="left"

            android:orientation="horizontal">

            <RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                android:text="男"
                android:textSize="20dp"/>
            <RadioButton
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                android:text="女"
                android:textSize="20dp"/>
        </RadioGroup>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="left"
        android:orientation="horizontal">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="10dp"
            android:text="专业"
            android:textSize="20dp"/>
        <Spinner
            android:id="@+id/chose"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="15dp"
            android:prompt="@string/eduprompt"
            android:entries="@array/edu"
            android:spinnerMode="dialog"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="left"
        android:layout_marginTop="20dp"
        android:orientation="vertical">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="兴趣爱好"
            android:textSize="20dp"
            android:layout_marginLeft="10dp"/>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="left"
            android:orientation="horizontal">
            <CheckBox
                android:id="@+id/box1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:textSize="18dp"
                android:text="音乐"/>
            <CheckBox
                android:id="@+id/box2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:textSize="18dp"
                android:text="运动"/>
        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="left"
            android:orientation="horizontal">
            <CheckBox
                android:id="@+id/box3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:textSize="18dp"
                android:text="游泳"/>
            <CheckBox
                android:id="@+id/box4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:textSize="18dp"
                android:text="阅读"/>
        </LinearLayout>
    </LinearLayout>

    <LinearLayout
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <Button
            android:id="@+id/tixing"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="提交"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="取消"/>
    </LinearLayout>

</LinearLayout>

strings.xml

<resources>
    <string name="app_name">text2</string>
    <string name="eduprompt">请选择你的专业</string>
</resources>

edu.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="edu">
        <item>计算机科学与技术</item>
        <item>大数据开发</item>
        <item>信息安全</item>
        <item>人工智能</item>
    </string-array>
</resources>

实验2.2-1

MainActivity.java

package com.example.text22;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.HashMap;

public class MainActivity extends AppCompatActivity {
    private String listdata[] = {
        "移动应用开发技术","计算机组成原理","数据结构","操作系统","面向对象技术","逻辑设计"
        };
    private ListView listview;
    private TextView textview;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
           
        this.textview = (TextView) super.findViewById(R.id.title) ;
        this.listview = (ListView) super.findViewById(R.id.Mylistview);
        
        
        this.listview.setAdapter(new ArrayAdapter<String>(this,
                                                          android.R.layout.simple_expandable_list_item_1,
                                                          this.listdata));
        
        listview.setOnItemClickListener(new AdapterView.OnItemClickListener(){
            @Override
            public void onItemClick(AdapterView<?> arg0,View arg1,int arg2,long arg3)
            {
                String text = (String) listview.getItemAtPosition(arg2);
                textview.setText(text);
            }
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:app="http://schemas.android.com/apk/res-auto"
              xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:orientation="vertical"
              tools:context=".MainActivity">
  
  <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="MenuDemo"
            android:layout_marginLeft="20dp"
            android:gravity="left"
            android:textSize="20dp"/>
  
  <ListView
            android:id="@+id/Mylistview"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
  
  
  
  
</LinearLayout>

实验效果

---

实验2.2-2

Mainactivity.java

package com.example.test22_2;

import androidx.appcompat.app.AppCompatActivity;

import android.app.ListActivity;
import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;


import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MainActivity extends AppCompatActivity {
    private ListView listView;
    private List<Map<String,Object>> list;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        list = new ArrayList<Map<String,Object>>();
        listView = (ListView) findViewById(R.id.listView);
        
        Map<String,Object> map1 = new HashMap<String,Object>();
        Map<String,Object> map2 = new HashMap<String,Object>();
        Map<String,Object> map3 = new HashMap<String,Object>();
        Map<String,Object> map4 = new HashMap<String,Object>();
        Map<String,Object> map5 = new HashMap<String,Object>();
        Map<String,Object> map6 = new HashMap<String,Object>();
        
        map1.put("title","姓名");
        map1.put("info","李坤松");
        map1.put("picture",R.drawable.img);
        list.add(map1);
        map2.put("title","性别");
        map2.put("info","男");
        map2.put("picture",R.drawable.img);
        list.add(map2);
        
        map3.put("title","学号");
        map3.put("info","2012020047");
        map3.put("picture",R.drawable.img);
        list.add(map3);
        map4.put("title","年龄");
        map4.put("info","19");
        map4.put("picture",R.drawable.img);
        list.add(map4);
        map5.put("title","居住地");
        map5.put("info","开封");
        map5.put("picture",R.drawable.img);
        list.add(map5);
        map6.put("title","邮箱");
        map6.put("info","2012020047@henu.edu.cn");
        map6.put("picture",R.drawable.img);
        list.add(map6);
        
        
        //        SimpleAdapter simpleAdapter = new SimpleAdapter(this,list,R.layout.user,new String[]
        //                {"title","info","picture"},
        //                new int[] {R.id.title,R.id.info,R.id.picture});
        MyAdapter adapter = new MyAdapter(this,list,R.layout.user);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                adapter.setCurrentItem(i);
                adapter.setClick(true);
                adapter.notifyDataSetChanged();
            }
        });
        
    }
    class MyAdapter extends BaseAdapter {
        private Context context;
        private int resource;
        private List<Map<String,Object>> list;
        private int mCurrentItem=0;
        private boolean isClick=false;
        
        /**
        * 有参构造
        *
        * @param context
        *            界面
        * @param list
        *            数据
        * @param resource
        *            列表项资源文件
        */
        
        public MyAdapter(Context context, List<Map<String, Object>> list, int resource) {
            this.context = context;
            this.list = list;
            this.resource = resource;
        }
        
        @Override
        public int getCount() {
            return list.size();
        }
        
        @Override
        public Object getItem(int i) {
            return list.get(i);
        }
        
        @Override
        public long getItemId(int i) {
            return i;
        }
        
        @Override
        public View getView(int i, View view, ViewGroup viewGroup) {
            // 声明内部类
            Util util = null;
            
            final int flag = i;
            
            if(view == null){
                util = new Util();
                // 给xml布局文件创建java对象
                LayoutInflater inflater = LayoutInflater.from(context);
                view = inflater.inflate(resource, null);
                // 指向布局文件内部组件
                util.picture = (ImageView) view.findViewById(R.id.picture);
                util.info = (TextView) view.findViewById(R.id.info);
                util.title = (TextView) view.findViewById(R.id.title);
                // 增加额外变量
                view.setTag(util);
            }
            else {
                util = (Util) view.getTag();
            }
            // 获取数据显示在各组件
            Map<String, Object> map = list.get(i);
            util.info.setText((String) map.get("info"));
            util.title.setText((String) map.get("title"));
            util.picture.setImageResource((Integer) map.get("picture"));
            
            
            LinearLayout parent= (LinearLayout) view.findViewById(R.id.parent1);
            
            if (mCurrentItem==i&&isClick){
                parent.setBackgroundColor(Color.parseColor("#708090"));
            }else{
                parent.setBackgroundColor(Color.parseColor("#FFB6C1"));
            }
            
            return view;
        }
        
        
        
        public void setCurrentItem(int currentItem){
            this.mCurrentItem=currentItem;
        }
        
        public void setClick(boolean click){
            this.isClick=click;
        }
        /**
        * 内部类，用于辅助适配
        *
        * @author qiangzi
        *
        */
        class Util{
            TextView title;
            TextView info;
            ImageView picture;
        }
    }
}

activity.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:app="http://schemas.android.com/apk/res-auto"
              xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical"
              tools:context=".MainActivity">
  
  <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="个人信息"
            android:textSize="20dp"/>
  
  <ListView
            android:id="@+id/listView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
  
</LinearLayout>

user.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:id="@+id/parent1"
              android:cacheColorHint = "#2BE4D3">
  
  <ImageView
             // 图片在res/drawabale里面,自己放
             android:id="@+id/picture"
             android:layout_width="100dp"
             android:layout_height="80dp"
             android:layout_margin="5dip"/>
  <LinearLayout
                android:orientation="vertical"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content">
    <TextView
              android:id="@+id/title"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:textSize="22sp"/>
    <TextView
              android:id="@+id/info"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:textSize="16sp"/>
    
  </LinearLayout>
  
  
</LinearLayout>

实验效果

实验2.3

Mainactivity.java

package com.example.a23;

import androidx.appcompat.app.AppCompatActivity;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    private Button fir = null;
    private Button sec = null;
    private Button thr = null;
    private Button fou = null;
    private Button fif = null;

    private Button round = null;
    private Button stra = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        this.fir = (Button)super.findViewById(R.id.fir);
        this.sec = (Button)super.findViewById(R.id.sec);
        this.thr = (Button)super.findViewById(R.id.thr);
        this.fou = (Button)super.findViewById(R.id.fou);
        this.fif = (Button)super.findViewById(R.id.fif);


        // 进度条
        this.round = (Button)super.findViewById(R.id.round);
        this.stra = (Button)super.findViewById(R.id.stra);



        // 调用buclick 里面的alertdialog方法
        fir.setOnClickListener(new buclick.click());
        sec.setOnClickListener(new buclick.click());
        thr.setOnClickListener(new buclick.click());
        fou.setOnClickListener(new buclick.click());
        fif.setOnClickListener(new buclick.click());

        round.setOnClickListener(new buclick.click());
        stra.setOnClickListener(new buclick.click());


    }



}

buclick.java

package com.example.a23;

import android.app.AlertDialog;
import android.app.DatePickerDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class buclick {

    private Context context;

    public Context getContxt() {
        return context;
    }
    public void setContxt(Context contxt) {
        this.context = (MainActivity) contxt;
    }

    public static class click implements View.OnClickListener{

        @Override
        public void onClick(View v) {
            switch (v.getId()) {
                // 分类对每个按钮的alertdialog进行设置
                case R.id.fir:
                    AlertDialog.Builder dialog = new AlertDialog.Builder (v.getContext());
                    dialog.setTitle("删除对话框");
                    dialog.setMessage("确定要删除对话框嘛");
                    dialog.setIcon(R.drawable.fir);
                    dialog.setCancelable(false);
                    dialog.setPositiveButton("是", new DialogInterface.
                            OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                        }
                    });
                    dialog.setNegativeButton("否", new DialogInterface.
                            OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                        }
                    });
                    dialog.setNeutralButton("查看详情",new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog,int which){

                        }
                    });
                    dialog.show();
                    break;
                case R.id.sec:
                    AlertDialog.Builder dialog2 = new AlertDialog.Builder (v.getContext());
                    dialog2.setTitle("你喜欢吃哪种水果");
                    dialog2.setIcon(R.drawable.fir);
                    dialog2.setCancelable(false);

                    dialog2.setItems(new String[]{"苹果","芒果","草莓","香蕉"},new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog,int which){

                        }
                    });

                    dialog2.setNeutralButton("取消",new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog,int which){

                        }
                    });
                    dialog2.show();
                    break;
                case R.id.thr:
                    AlertDialog.Builder dialog3 = new AlertDialog.Builder (v.getContext());
                    dialog3.setTitle("你喜欢吃哪种水果");
                    dialog3.setIcon(R.drawable.fir);
                    dialog3.setCancelable(false);

                    // 单选框
                    dialog3.setSingleChoiceItems(new String[]{"苹果","芒果","草莓","香蕉"},0,
                            new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog,int which){

                        }
                    });

                    dialog3.setPositiveButton("确认",new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog,int which){

                        }
                    });
                    dialog3.setNegativeButton("取消",new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog,int which){

                        }
                    });
                    dialog3.show();
                    break;
                case R.id.fou:
                    AlertDialog.Builder dialog4 = new AlertDialog.Builder (v.getContext());
                    dialog4.setTitle("你喜欢吃哪种水果");
                    dialog4.setIcon(R.drawable.fir);
                    dialog4.setCancelable(false);

                    // 多选框
                    dialog4.setMultiChoiceItems(new String[]{"苹果","芒果","草莓","香蕉"},
                            null,null);

                    dialog4.setPositiveButton("确认",new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog,int which){

                        }
                    });
                    dialog4.setNegativeButton("取消",new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog,int which){

                        }
                    });
                    dialog4.show();
                    break;
                case R.id.fif:
                    AlertDialog.Builder dialog5 = new AlertDialog.Builder (v.getContext());
                    dialog5.setCancelable(false);
                    dialog5.setIcon(R.drawable.fir);
                    dialog5.setTitle("用户登录");
                    dialog5.setView(R.layout.dialog);
                    dialog5.setPositiveButton("登录",new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog , int which){

                        }
                    });
                    dialog5.setNegativeButton("取消",new DialogInterface.OnClickListener(){
                        @Override
                        public void onClick(DialogInterface dialog , int which){

                        }
                    });
                    dialog5.show();
                    break;
                case R.id.round:
                    ProgressDialog round = new ProgressDialog(v.getContext());
                    round.setIcon(R.drawable.fir);
                    round.setTitle("提示");
                    round.setMessage("这是一个圆形进度条");
                    round.setCancelable(true);
                    round.show();
                    break;
                case R.id.stra:
                    ProgressDialog stra = new ProgressDialog(v.getContext());
                    stra.setIcon(R.drawable.fir);
                    stra.setTitle("提示");
                    stra.setMessage("这是一个长条形进度对话框");
                    stra.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
                    stra.setMax(100);
                    stra.setCancelable(true);
                    stra.show();
                    Task t = new Task(stra);
                    t.start();
                    break;
                default:
                    break;
            }
        }
    }
//    为条形进度条添加run方法
    private static class Task extends Thread {
//为了避免死循环，定义一个控制变量，使得程序不会死掉
        boolean run = true;
        ProgressDialog stra;

        Task(ProgressDialog p) {
            stra = p;
        }

        @Override
        public void run() {
            while (run) {
                try {

                    stra.setProgress(stra.getProgress() + 1);
                    if (stra.getProgress() >= 100) {
                        stra.cancel();
                        run = false;
                    }
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    run = false;//产生异常的时候，让他停止
                }
            }
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/fir"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="75dp"
        android:layout_gravity="center"
        android:text="确认对话框"/>

    <Button
        android:id="@+id/sec"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="列表对话框"/>

    <Button
        android:id="@+id/thr"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="单选对话框"/>

    <Button
        android:id="@+id/fou"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="多选对话框"/>

    <Button
        android:id="@+id/fif"

        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="自定义对话框"/>

    <Button
        android:id="@+id/round"

        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="圆形进度条对话框"/>

    <Button
        android:id="@+id/stra"
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="条形进度条对话框"/>



</LinearLayout>

dialog.xml

(在layout文件夹里面)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:id="@+id/dialog"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:layout_marginLeft="3dp"
            android:layout_marginRight="3dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text = "用户名:"
            android:id="@+id/name"/>

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/mname"/>

    </LinearLayout>
    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:layout_marginLeft="3dp"
            android:layout_marginRight="9dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text = "密码: "
            android:id="@+id/password"/>

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/mpassword"/>

    </LinearLayout>


</LinearLayout>

修改button的背景颜色

1. 打开values文件夹里面的themes里面第一个themes.xml文件

2. 修改里面的第二行

   <style name="Theme.23" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
   改为：
   <style name="Theme.23" parent="Theme.MaterialComponents.DayNight.DarkActionBar.Bridge">

3. 修改后初始界面就变成灰色了，而不是一开始的蓝紫色了

效果图

TabHost

注释：此次并非实验指导书上要求的代码，是书上的源码，只是为了方便理解，2.4实验就不再重新写

activity_main.xml(顶部导航)

<?xml version="1.0" encoding="utf-8"?>

<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/tabhost"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <!--顶部导航-->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <!--     TabWidget   每个Tab的选项，即Tab标签-->
        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true" />

        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="match_parent"
            android:layout_height="match_parent">
            <!--Tab页1-->
            <LinearLayout
                android:id="@+id/file"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center_horizontal"
                android:orientation="vertical">

                <Button
                    android:id="@+id/open"
                    android:layout_width="150dp"
                    android:layout_height="wrap_content"
                    android:text="打开文件" />

                <Button
                    android:id="@+id/save"
                    android:layout_width="150dp"
                    android:layout_height="wrap_content"
                    android:text="保存文件" />

                <Button
                    android:id="@+id/saveAs"
                    android:layout_width="150dp"
                    android:layout_height="wrap_content"
                    android:text="文件另存为" />
            </LinearLayout>
            <!--Tab页2-->
            <LinearLayout
                android:id="@+id/edit"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center_horizontal"
                android:orientation="vertical">

                <Button
                    android:id="@+id/copy"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="复制" />

                <Button
                    android:id="@+id/paste"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="粘贴" />
            </LinearLayout>
            <!--Tab页3-->
            <LinearLayout
                android:id="@+id/seek"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center_horizontal"
                android:orientation="vertical">

                <EditText
                    android:id="@+id/edit1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="请输入检索关键字..."
                    android:textSize="18sp" />

                <Button
                    android:id="@+id/seekbut1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="搜索" />
            </LinearLayout>
            <!--Tab页4-->
            <LinearLayout
                android:id="@+id/time"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center_horizontal"
                android:orientation="vertical">

                <TimePicker
                    android:id="@+id/seekbut"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="设置时间" />
            </LinearLayout>
        </FrameLayout>
    </LinearLayout>
</TabHost>

activity_three.xml（底部导航）

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/tabhost"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <!--实现底部导航-->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            <LinearLayout
                android:id="@+id/file"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center_horizontal"
                android:orientation="vertical">

                <Button
                    android:id="@+id/open"
                    android:layout_width="150dp"
                    android:layout_height="wrap_content"
                    android:text="打开文件" />

                <Button
                    android:id="@+id/save"
                    android:layout_width="150dp"
                    android:layout_height="wrap_content"
                    android:text="保存文件" />

                <Button
                    android:id="@+id/saveAs"
                    android:layout_width="150dp"
                    android:layout_height="wrap_content"
                    android:text="文件另存为" />
            </LinearLayout>

            <LinearLayout
                android:id="@+id/edit"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center_horizontal"
                android:orientation="vertical">

                <Button
                    android:id="@+id/copy"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="复制" />

                <Button
                    android:id="@+id/paste"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="粘贴" />
            </LinearLayout>

            <LinearLayout
                android:id="@+id/seek"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center_horizontal"
                android:orientation="vertical">

                <EditText
                    android:id="@+id/edit1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="请输入检索关键字..."
                    android:textSize="18sp" />

                <Button
                    android:id="@+id/seekbut1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="搜索" />
            </LinearLayout>

            <LinearLayout
                android:id="@+id/time"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center_horizontal"
                android:orientation="vertical">

                <TimePicker
                    android:id="@+id/seekbut"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="设置时间" />
            </LinearLayout>
        </FrameLayout>

        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_weight="0" />
    </LinearLayout>
</TabHost>

MainActivity.java

package com.example.a31;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TabHost;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private TabHost myTabHost;                    //定义TabHost
    private int[] layRes = {R.id.file, R.id.edit, R.id.seek, R.id.time};//定义内嵌布局管理器ID
    private Button openButton;

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.open:
                Toast.makeText(MainActivity.this, "这是打open按钮", Toast.LENGTH_LONG).show();
                break;
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_three);
        myTabHost = findViewById(R.id.tabhost); //取得TabHost对象

        myTabHost.setup();
        //建立TabHost对象
        TabHost.TabSpec myTab1 = myTabHost.newTabSpec("文件");    //定义TabSpec
        myTab1.setIndicator("File");                            //设置选项文字
        myTab1.setContent(layRes[0]);                //设置显示的组件
        myTabHost.addTab(myTab1);                    //增加选项


        TabHost.TabSpec myTab2 = myTabHost.newTabSpec("编辑");    //定义TabSpec
        myTab2.setIndicator("Edit").setContent(layRes[1]);                //设置显示的组件
        myTabHost.addTab(myTab2);                    //增加选项

        TabHost.TabSpec myTab3 = myTabHost.newTabSpec("查看");    //定义TabSpec
        myTab3.setIndicator("View").setContent(layRes[2]);                //设置显示的组件
        myTabHost.addTab(myTab3);                    //增加选项

        TabHost.TabSpec myTab4 = myTabHost.newTabSpec("设置")    //定义TabSpec
                .setIndicator("Set")                   //设置选项文字
                .setContent(layRes[3]);                //设置显示的组件
        myTabHost.addTab(myTab4);                    //增加选项

        myTabHost.setCurrentTab(0);                //设置开始默认选项
//        myTabHost.setCurrentTabByTag("文件");
        openButton = findViewById(R.id.open);
        openButton.setOnClickListener(this);
        //选项切换事件处理，setOnTabChangedListener
        myTabHost.setOnTabChangedListener(new TabHost.OnTabChangeListener() {
            public void onTabChanged(String tabId) {
            }
        });
    }
}

效果图

实验三

实验3.1

MainActivity.java

package com.example.a3_11;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MainActivity extends AppCompatActivity {

    private String listdata[] = {"李四","张三","王五","陈六","宋七"};
    private ListView listView;
    private List<String> list;
    private ArrayAdapter adpter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView = (ListView)findViewById(R.id.listview);
        // 将listdata的数据导入到list的 数组中,通过删除数组的元素，来实现删除操作
        list = new ArrayList<String>(Arrays.asList(listdata));

        // 使用ArrayAdapter的适配器
        adpter = new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1
                ,this.list);
        this.listView.setAdapter(adpter);

        // listview 的点击事件
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                // 向 MainActivity.java传入数据
                String name = (String)listView.getItemAtPosition(i);
                Intent it = new Intent(MainActivity.this,MainActivity2.class);
                it.putExtra("sendinfo",name);
                it.putExtra("value",i);
                startActivityForResult(it,1);
                adpter.notifyDataSetChanged();
            }
        });
    }

    // 定义一个方法，用来删除数据
    public void delete(ArrayAdapter adapterView, int i)
    {
        String text = (String)listView.getItemAtPosition(i);
        // 删除listview 中第i个数据
        adpter.remove(listView.getItemAtPosition(i));
        Toast.makeText(getApplicationContext(),text+"的记录已被删除",Toast.LENGTH_LONG).show();
    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            case 1:
                if(resultCode == RESULT_OK)
                {
                    // 返回点击该项的索引
                    int h = data.getIntExtra("return",1);
                    // 调用删除的方法
                    delete(adpter,h);
                }
                else {
                    String text = "取消操作";
                    Toast.makeText(getApplicationContext(),text,Toast.LENGTH_LONG).show();
                }
            default:
                break;
        }
    }
}

MainActivity2.java

package com.example.a3_11;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        // 获得Mainactivity.java提供过来的参数
        Intent it = super.getIntent();
        String info = it.getStringExtra("sendinfo"); // listview的内容
        int position = it.getIntExtra("value",1); // 点击的数组索引

        // 对xml中的布局变量进行注册
        Button btn1= (Button) findViewById(R.id.fir);
        Button btn2 = (Button) findViewById(R.id.sec);
        TextView txt = (TextView) findViewById(R.id.txt);


        txt.setText("删除 "+info+" 的记录吗?");

        // 调用两个按钮的点击事件
        // 确定按钮
        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 向main activity 返回点击的状态，从而执行删除操作
                getIntent().putExtra("return",position);
                setResult(RESULT_OK,MainActivity2.this.getIntent());
                finish();
            }
        });
        // 取消按钮
        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // 按钮2 是取消操作
                Intent it2 = new Intent();
                setResult(RESULT_CANCELED,it2);
                finish();
            }
        });
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">


<!--    测试返回的值-->
<!--    <EditText-->
<!--        android:id="@+id/mag"-->
<!--        android:text="nihao"-->
<!--        android:layout_width="match_parent"-->
<!--        android:layout_height="wrap_content"/>-->

    <ListView
        android:id="@+id/listview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>



</LinearLayout>

activity_main2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity2">

    <TextView
        android:id="@+id/txt"
        android:text=""
        android:layout_marginLeft="40dp"
        android:textSize="20dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <LinearLayout
        android:id="@+id/text"
        android:orientation="horizontal"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">


        <Button
            android:id="@+id/fir"
            android:layout_width="150dp"
            android:layout_marginRight="10dp"
            android:layout_height="wrap_content"
            android:text="确认"/>

        <Button
            android:id="@+id/sec"
            android:layout_marginLeft="10dp"
            android:layout_width="150dp"
            android:layout_height="wrap_content"
            android:text="取消"/>

    </LinearLayout>

</LinearLayout>

实验结果：

HashMap 和Map区别

Map

1. Map集合一次存储两个对象，一个键对象，一个值对象
2. 键对象在集合中是唯一的，可以通过键来查找值

HashMap

1. 使用哈希算法对键去重复，效率高，但无序
2. HashMap是Map接口的主要实现类

ArrayList

List是一个接口，而ArrayList是List接口的一个实现类

ArrayList<E> objectName =new ArrayList<>();　 // 初始化

ArrayList<String> sites = new ArrayList<String>();
        sites.add("Google");
        sites.add("Runoob");
        sites.add("Taobao");
        sites.add("Weibo");
        sites.set(2, "Wiki"); // 第一个参数为索引位置，第二个为要修改的值
		sites.remove(3); // 删除第四个元素
		System.out.println(sites.size());

• E: 泛型数据类型，用于设置 objectName 的数据类型，只能为引用数据类型。
• objectName: 对象名。

实验3.2

MainActivity

package com.henu.a3_2;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.NotificationCompat;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

import java.nio.channels.Channel;

public class MainActivity extends AppCompatActivity {

    private int id = 1;
    private static final String TAG ="" ;
    private static final int MAX = 1000;
    private Context context;
    private NotificationManager notificationManager;
    private Notification notification;
    private String Channeld;
    private CharSequence ChannelName;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        String id = "my_channel_01";
        String name="我是渠道名字";
        notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        notification = null;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel mChannel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_LOW);
            notificationManager.createNotificationChannel(mChannel);
            notification = new NotificationCompat.Builder(this,"chat")
                    .setChannelId(id)
                    .setLargeIcon(BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher))
                    .setContentTitle("5 new messages")
                    .setWhen(System.currentTimeMillis())
                    .setContentText("2012020047 - lks")
                    .setPriority(NotificationCompat.PRIORITY_HIGH)
                    .setSmallIcon(R.drawable.fir).build();
        } else {
            NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this,"subscribe")
                    .setContentTitle("5 new messages")
                    .setContentText("hahaha")
                    .setSmallIcon(R.drawable.fir)
                    .setOngoing(true);
            notification = notificationBuilder.build();
        }



    }

    public void send(View view){
        notificationManager.notify(id ++, notification);
    }

    public void clean(View view){
        for(int i = 1;i <= id ;i ++){
            notificationManager.cancel(i);
        }
    }

}

MyRecevier.java

新建一个广播类

package com.henu.a3_2;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.widget.Toast;

import androidx.annotation.RequiresApi;
import androidx.core.app.NotificationCompat;

public class MyReceiver extends BroadcastReceiver {

    private NotificationManager notificationManager;
    private Notification notification;

    @RequiresApi(api = Build.VERSION_CODES.O)
    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context, "111", Toast.LENGTH_SHORT).show();
        // TODO: This method is called when the BroadcastReceiver is receiving
        // an Intent broadcast.
//        throw new UnsupportedOperationException("Not yet implemented");
//        Intent service = new Intent(context,MyService.class);
//        context.startService(service);
        String id = "my_channel_01";
        String name="我是渠道名字";
        notificationManager = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
        notification = null;
        NotificationChannel mChannel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_LOW);
        notificationManager.createNotificationChannel(mChannel);
        notification = new NotificationCompat.Builder(context)
                .setChannelId(id)
                .setContentTitle("5 new messages")
                .setWhen(System.currentTimeMillis())
                .setContentText("2012020047 - lks")
                .setPriority(NotificationCompat.PRIORITY_HIGH)
                .setSmallIcon(R.drawable.fir).build();

        notificationManager.notify(1,notification);
    }

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:layout_centerHorizontal="true"
    tools:context=".MainActivity">

    <Button
        android:onClick="send"
        android:text="发送广播消息"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
    <Button
        android:onClick="clean"
        android:text="清除通知图标"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

AndroidManifest.xml （在里面注册广播和开机自启动）

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.henu.a3_2">

    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" /> <!--接收开机的广播-->

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.32">
        <!--接收开机的广播-->
        <receiver
            android:name=".MyReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED"/>
            </intent-filter>
        </receiver>

        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

实验结果

正常运行

开机启动后

点击发送广播后

实验四

实验4.1

MainActivity.java

package com.henu.a4_1;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button start1 = (Button) super.findViewById(R.id.fir);
        Button end1 = (Button) super.findViewById(R.id.sec);

        start1.setOnClickListener(this);
        end1.setOnClickListener(this);

    }

    @Override
    public void onClick(View v){
        switch (v.getId()){
            case R.id.fir:
                Intent start = new Intent(this,MyService.class);
                startService(start);
                break;
            case R.id.sec:
                Intent stop = new Intent(this,MyService.class);
                stopService(stop);
                break;
            default:
                break;
        }
    }
}

MyService.java

新建一个Service类，选第一个service，会自动帮你在 AndroidManifest.xml 中注册好

package com.henu.a4_1;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Build;
import android.os.IBinder;
import android.util.Log;

import androidx.annotation.RequiresApi;
import androidx.core.app.NotificationCompat;

public class MyService extends Service {

    private static final String TAG = "MyService";
    private NotificationManager notificationManager;
    private Notification notification;
    private boolean flag = false;
    private boolean time = false;
    private int id = 0;

    public MyService() {
    }

    @RequiresApi(api = Build.VERSION_CODES.O)
    // 设置一个线程，用来循环显示两个通知
    Runnable notice = new Runnable() {
        @RequiresApi(api = Build.VERSION_CODES.O)
        @Override
        public void run() {
            Log.d(TAG,"启动成功");
            // 当time不为空，就一直循环
            while(!time)
            {
                // 利用flag 进行两个通知之间的切换
                if(!flag){
                    flag = true;
                    String id = "my_channel_01";
                    String name="我是渠道名字";
                    notificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
                    notification = null;
                    NotificationChannel mChannel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_LOW);
                    notificationManager.createNotificationChannel(mChannel);
                    notification = new NotificationCompat.Builder(getApplicationContext())
                            .setChannelId(id)
                            .setContentTitle("fir")
                            .setWhen(System.currentTimeMillis())
                            .setContentText("2012020047 - lks")
                            .setSmallIcon(R.drawable.fir).build();
                    notificationManager.notify(1,notification);


                }else if(flag){
                    flag = false;
                    String id = "my_channel_01";
                    String name="我是渠道名字";
                    notificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
                    notification = null;
                    NotificationChannel mChannel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_LOW);
                    notificationManager.createNotificationChannel(mChannel);
                    notification = new NotificationCompat.Builder(getApplicationContext())
                            .setChannelId(id)
                            .setContentTitle("sec")
                            .setWhen(System.currentTimeMillis())
                            .setContentText("2012020047 - lks")
                            .setSmallIcon(R.drawable.time).build();
                    notificationManager.notify(1,notification);
                }
                // 设置延迟时间
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    };


    @RequiresApi(api = Build.VERSION_CODES.O)
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG,"onstart ");
        Thread thread = new Thread(notice);
        if(!thread.isAlive()){
            thread.start();
        }
        return super.onStartCommand(intent, flags, startId);
    }

    // 关闭服务
    @Override
    public void onDestroy() {
        Log.d(TAG,"destroy");
        // time = true 关闭线程
        time = true;
        // q
        notificationManager.cancel(1);
        super.onDestroy();
    }

    @Override
    public void onCreate() {
        Log.d(TAG,"oncreate ");
        super.onCreate();
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        return null;
    }
}

antivity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/fir"
        android:text="启动服务"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <Button
        android:id="@+id/sec"
        android:text="关闭服务"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

实验结果：

点击启动之后，每个一秒更新通知栏中的通知，交替显示两个不同的图标，点击关闭服务，服务停止，通知栏图标被关闭

实验4.2

MainActivity.java

package com.henu.a4_2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private static final String TAG = "MainActivity";
    private MyService.MyBinder mybinder;
    // 获取服务
    private MyService myService = new MyService();

    private ServiceConnection connection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            Log.i("MainActivity","执行了onServiceConnected(),当前Acitivity与服务连接成功");
            mybinder =(MyService.MyBinder) iBinder;

        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            Log.i("MainActivity","执行了onServiceDisconnected(),当前Acitivity与服务断开连接");
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button fir = (Button) super.findViewById(R.id.fir);
        Button sec = (Button) super.findViewById(R.id.sec);
        Button thr = (Button) super.findViewById(R.id.thr);
        Button fou = (Button) super.findViewById(R.id.fou);

        fir.setOnClickListener(this);
        sec.setOnClickListener(this);
        thr.setOnClickListener(this);
        fou.setOnClickListener(this);

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.fir:
                Intent bindIntent = new Intent(this,MyService.class);
                bindService(bindIntent,connection,BIND_AUTO_CREATE);
                contant.nh = 1000;
                break;
            case R.id.sec:
                unbindService(connection);
                break;
            case R.id.thr:
                myService.fast();
                break;
            case R.id.fou:
                myService.slow();
                break;
            default:
                break;
        }
    }

}

MyService.java

创建一个service，方法参考上文4.1MyService的创建方法

package com.henu.a4_2;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.Build;
import android.os.IBinder;
import android.util.Log;

import androidx.annotation.RequiresApi;
import androidx.core.app.NotificationCompat;

public class MyService extends Service {
    private static final String TAG = "MyService";
    private MyBinder mBinder = new MyBinder();

    private NotificationManager notificationManager;
    private Notification notification;
    private boolean flag = false;
    private boolean time = false;

    // 新建一个线程
    Runnable notice = new Runnable() {
        @RequiresApi(api = Build.VERSION_CODES.O)
        public void run() {
            Log.d(TAG,"启动成功");
            // 当time不为空，就一直循环
            while(!time)
            {
                // 利用flag 进行两个通知之间的切换
                if(!flag){
                    flag = true;
                    String id = "my_channel_01";
                    String name="我是渠道名字";
                    notificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
                    notification = null;
                    NotificationChannel mChannel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_LOW);
                    notificationManager.createNotificationChannel(mChannel);
                    notification = new NotificationCompat.Builder(getApplicationContext())
                            .setChannelId(id)
                            .setContentTitle("fir")
                            .setWhen(System.currentTimeMillis())
                            .setContentText("2012020047 - lks")
                            .setSmallIcon(R.drawable.fir).build();
                    notificationManager.notify(1,notification);
                }else if(flag){
                    flag = false;
                    String id = "my_channel_01";
                    String name="我是渠道名字";
                    notificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
                    notification = null;
                    NotificationChannel mChannel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_LOW);
                    notificationManager.createNotificationChannel(mChannel);
                    notification = new NotificationCompat.Builder(getApplicationContext())
                            .setChannelId(id)
                            .setContentTitle("sec")
                            .setWhen(System.currentTimeMillis())
                            .setContentText("2012020047 - lks")
                            .setSmallIcon(R.drawable.time).build();
                    notificationManager.notify(1,notification);
                }
                // 设置延迟时间
                int h = contant.nh;
                Log.i(TAG,""+h);
                try {
                    Thread.sleep(h);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    };

    // 用来改变contant中的nh值，从而改变thread的睡眠时间
    public void fast(){
        contant.nh = 333;
    }
    public void slow(){
        contant.nh = 2000;
    }


    public class MyBinder extends Binder{

    }


    public MyService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
//        throw new UnsupportedOperationException("Not yet implemented");
        return mBinder;
    }

    @Override
    public boolean onUnbind(Intent intent) {
        Log.i("MyService","执行了onUnbind(),服务解绑成功");
        return super.onUnbind(intent);
    }

    @Override
    public void onCreate() {
        Log.i("MyService","执行了onCreste(),服务创建成功");
        Thread thread = new Thread(notice);
        if(!thread.isAlive()){
            thread.start();
        }
        super.onCreate();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.i("MyService","执行了onStartCommand(),服务启动成功");
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        time = true;
        notificationManager.cancel(1);
        Log.i("MyService","执行了onDestroy(),服务被销");
        super.onDestroy();
    }

}

contant.java

package com.henu.a4_2;

// 设置静态类，用来设置thread的sleep速率
public class contant {
    public static int  nh ;

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/fir"
        android:text="绑定服务"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <Button
        android:id="@+id/sec"
        android:text="取消绑定"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <Button
        android:id="@+id/thr"
        android:text="加速"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <Button
        android:id="@+id/fou"
        android:text="减速"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>


</LinearLayout>

实验效果

实验五

实验5.1

MainActivity.java

package com.example.a5_1;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;
import android.content.DialogInterface;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Spinner;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private Database dbt; // 数据库操作
    private String info; // 姓名
    private Spinner textspinner;
    private String getContent; // 获取下拉框的内容
    private String gender1; // 获取性别
    private StringBuffer sbt; // 获取爱好
    private EditText name = null;
    private Button tixing = null;
    private RadioGroup rex;// 单选框的组
    private RadioButton man,women;
    private CheckBox box1 , box2 , box3, box4;

    private List<CheckBox> checkBoxList = new ArrayList<CheckBox>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        dbt = new Database(this,"people.db",null,1);

        this.name = (EditText)super.findViewById(R.id.edit1);

        man = (RadioButton) super.findViewById(R.id.man);
        women = (RadioButton) super.findViewById(R.id.women);
        rex = (RadioGroup) super.findViewById(R.id.Radio1);
        textspinner = (Spinner) super.findViewById(R.id.chose) ;
        tixing = (Button)super.findViewById((R.id.tixing));
        box1 = (CheckBox)super.findViewById((R.id.box1));
        box2 = (CheckBox)super.findViewById((R.id.box2));
        box3 = (CheckBox)super.findViewById((R.id.box3));
        box4 = (CheckBox)super.findViewById((R.id.box4));

        checkBoxList.add(box1);
        checkBoxList.add(box2);
        checkBoxList.add(box3);
        checkBoxList.add(box4);

        tixing.setOnClickListener(new ShowListerer());
        man.setOnClickListener(this);
        women.setOnClickListener(this);
        textspinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener() {
            @Override
            /*public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

            }*/
            public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
                getContent = MainActivity.this.getResources().getStringArray(R.array.edu)[arg2];
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.man:
                gender1 = man.getText().toString().trim();
                break;
            case R.id.women:
                gender1 = women.getText().toString().trim();
                break;
        }
    }


    private class ShowListerer implements View.OnClickListener {
        public void onClick(View v)
        {
            sbt = new StringBuffer();
            for (CheckBox checkbox : checkBoxList) {
                if (checkbox.isChecked()){
                    sbt.append(checkbox.getText().toString() + " ");
                }
            }
            info = name.getText().toString();

            if(info.trim().equals(""))
            {
                Toast.makeText(MainActivity.this,"请输入姓名",Toast.LENGTH_LONG).show();
            }
            else
            {
                add(info,gender1,getContent,sbt.toString());
                Toast.makeText(MainActivity.this,"姓名是: "+info+"\n"+"性别: " +gender1+"\n"+"专业"+getContent+"\n"+"兴趣爱好 "+sbt.toString(),Toast.LENGTH_LONG).show();
                clean();
            }


        }
    }

    // 对数据库进行插入操作
    public void add(String name,String gender,String major,String hobby)
    {
        SQLiteDatabase db = dbt.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put("name",name);
        values.put("gender",gender);
        values.put("major",major);
        values.put("hobby",hobby);
        db.insert("peopleinfo",null,values);
    }

    // 清楚所有的状态
    public void clean(){
        // 设置名字为空
        name.setText("");
        // 设置下拉菜单不显示

        // 设置单选框不选中
        rex.clearCheck();
        // 设置多选框取消选中
        for (CheckBox checkbox : checkBoxList) {
            if (checkbox.isChecked()){
                checkbox.setChecked(false);
            }
        }
    }
}

Database.java

// database操作
package com.example.a5_1;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import androidx.annotation.Nullable;

public class Database extends SQLiteOpenHelper {

    public Database(@Nullable Context context, @Nullable String name, @Nullable SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, factory, version);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        //创建数据库sql语句并执行
        String sql="create table peopleinfo (id integer primary key autoincrement, name text not null, gender text, major text, hobby text )";
        db.execSQL(sql);

    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="left"
        android:layout_marginLeft="10dp"
        android:orientation="horizontal">
        <TextView
            android:id="@+id/name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="姓名:"
            android:textSize="20dp"
            android:layout_weight="1"/>

        <EditText
            android:id="@+id/edit1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="李坤松 2012020047"
            android:textSize="20dp"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="left"
        android:orientation="horizontal">
        <TextView
            android:id="@+id/gender"
            android:layout_marginLeft="10dp"
            android:layout_marginTop="19dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="性别"
            android:textSize="20dp" />
        <RadioGroup
            android:id="@+id/Radio1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="left"

            android:orientation="horizontal">

            <RadioButton
                android:id="@+id/man"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                android:text="男"
                android:textSize="20dp"/>
            <RadioButton
                android:id="@+id/women"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                android:text="女"
                android:textSize="20dp"/>
        </RadioGroup>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="left"
        android:orientation="horizontal">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="10dp"
            android:text="专业"
            android:textSize="20dp"/>
        <Spinner
            android:id="@+id/chose"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="15dp"
            android:prompt="@string/eduprompt"
            android:entries="@array/edu"
            android:spinnerMode="dialog"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="left"
        android:layout_marginTop="20dp"
        android:orientation="vertical">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="兴趣爱好"
            android:textSize="20dp"
            android:layout_marginLeft="10dp"/>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="left"
            android:orientation="horizontal">
            <CheckBox
                android:id="@+id/box1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:textSize="18dp"
                android:text="音乐"/>
            <CheckBox
                android:id="@+id/box2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:textSize="18dp"
                android:text="运动"/>
        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="left"
            android:orientation="horizontal">
            <CheckBox
                android:id="@+id/box3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:textSize="18dp"
                android:text="游泳"/>
            <CheckBox
                android:id="@+id/box4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"

                android:textSize="18dp"
                android:text="阅读"/>
        </LinearLayout>
    </LinearLayout>

    <LinearLayout
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <Button
            android:id="@+id/tixing"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="提交"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="取消"/>
    </LinearLayout>

</LinearLayout>

strings.xml

<resources>
    <string name="app_name">5_1</string>
    <string name="eduprompt">请选择你的专业</string>
</resources>

edu.xml(在res中的values中新建一个edu.xml文件)

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="edu">
        <item>计算机科学与技术</item>
        <item>大数据开发</item>
        <item>信息安全</item>
        <item>人工智能</item>
    </string-array>
</resources>

实验效果