androidstuido_schooltest_6_media_service

文章目录

• • activity_main.xml
  • MainActivity.java
  • MusicService.java

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
    tools:context=".MainActivity">

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >

        <Button
            android:id="@+id/btn_main_play"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="play" />

        <Button
            android:id="@+id/btn_main_stop"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="stop" />

        <Button
            android:id="@+id/btn_main_pause"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="pause" />

        <Button
            android:id="@+id/btn_main_exit"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="exit" />

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java

package com.kanxue.school_test_3;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    Button btn_main_play;
    Button btn_main_stop;
    Button btn_main_pause;
    Button btn_main_exit;
    //连接到播放文件
    MediaPlayer player=null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn_main_play = findViewById(R.id.btn_main_play);
        btn_main_stop = findViewById(R.id.btn_main_stop);
        btn_main_pause = findViewById(R.id.btn_main_pause);
        btn_main_exit = findViewById(R.id.btn_main_exit);
        btn_main_play.setOnClickListener(this);
        btn_main_stop.setOnClickListener(this);
        btn_main_pause.setOnClickListener(this);
        btn_main_exit.setOnClickListener(this);
        player=MediaPlayer.create(this,R.raw.water_hander);

    }
    @Override
    public void onClick(View v) {
        Intent intent= new Intent(MainActivity.this,MusicService.class);
        if(v.getId()==R.id.btn_main_play){
            intent.putExtra("action","play");
            startService(intent);
        }else if(v.getId()==R.id.btn_main_stop){
            intent.putExtra("action","stop");
            startService(intent);
           }else if(v==btn_main_pause){
            intent.putExtra("action","pause");
            startService(intent);
        }else if(v.getId()==R.id.btn_main_exit){
            stopService(intent);
            finish();
        }
    }


}

MusicService.java

package com.kanxue.school_test_3;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;

public class MusicService extends Service {
    public MediaPlayer player=null;
    public MusicService() {

    }
//启动service


    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
    //获取动作
        String action=intent.getStringExtra("action");
       if(action.equals("play")){
           if(player==null){
               player=MediaPlayer.create(this,R.raw.water_hander);
           }
           player.start();
       }else if(action.equals("pause")){
           player.pause();
       }else if(action.equals("stop")){
          if(player!=null){
              player.stop();
              player.reset();
              player.release();
              player=null;//注意不能少赋值null，否则出bug
          }
          }
        return super.onStartCommand(intent, flags, startId);
    }

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

    @Override
    public void onDestroy() {
        super.onDestroy();
        if(player!=null){
            player.stop();
            player.reset();
            player.release();
            player=null;//注意不能少赋值null，否则出bug
        }
    }
}