尝试后台服务时出现奇怪的结果

Question

我想在安卓上做一个井字游戏。它也有一些变体。我创建了一个后台服务类。相同的代码如下。

package com.sudarshan.tictactoenew;

import android.content.Intent;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.IBinder;
import android.app.Service;
import android.util.Log;

public class BackgroundSoundService extends Service {
    private static final String TAG = null;
   // Intent intent;

    MediaPlayer mp;
    public IBinder onBind(Intent arg0) {

        return null;
    }
    @Override
    public void onCreate() {
        super.onCreate();


    }
    public int onStartCommand(Intent intent, int flags, int startId) {

         mp = new MediaPlayer();

        Bundle extras = intent.getExtras();
        String itemname = (String) extras.get("itemname");
        Log.i("Itemname",itemname);
        if(itemname.equals("menupage"))
        {

            String filename = "android.resource://" + this.getPackageName() + "/raw/got";

            try {
                mp.setDataSource(this, Uri.parse(filename));
                mp.prepareAsync();
                mp.setLooping(true); // Set looping
                mp.setVolume(100,100);
                mp.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mp) {
                        mp.start();
                    }
                });
                    ;
            } catch(Exception e){
                e.printStackTrace();
            }
            // = MediaPlayer.create(this, R.raw.got);

           // player1.start();
        }
        else if(itemname.equals("classictictactoe"))
        {

            Log.i("Inside","Inside classic tic tac toe");
            String filename = "android.resource://" + this.getPackageName() + "/raw/cof";

            try {
                mp.setDataSource(this, Uri.parse(filename));
                mp.prepareAsync();
                mp.setLooping(true); // Set looping
                mp.setVolume(100,100);
                mp.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mp) {

                        mp.start();
                    }
                });
                
            } catch(Exception e){
                e.printStackTrace();
            }
            
        }


        return startId;
    }

    public void onStart(Intent intent, int startId) {
        // TO DO
    }
    public IBinder onUnBind(Intent arg0) {
        // TO DO Auto-generated method
        return null;
    }

    public void onStop() {

    }
    public void onPause() {

    }
    @Override
    public void onDestroy() {
        mp.stop();
        mp.release();


    }

    @Override
    public void onLowMemory() {

    }
}

此代码不会执行 Log.i("Inside","Inside classic tic tac toe"); 以下是我的日志文件部分

2022-10-02 21:44:36.475 13019-13019 Itemname                com.sudarshan.tictactoenew           I  menupage
2022-10-02 21:45:01.080 13019-13019 Itemname                com.sudarshan.tictactoenew           I  classictictactoe
2022-10-02 21:57:39.288 13019-13019 Itemname                com.sudarshan.tictactoenew           I  menupage
2022-10-02 21:57:46.764 13019-13019 Itemname                com.sudarshan.tictactoenew           I  classictictactoe
2022-10-02 21:57:57.114 13019-13019 Itemname                com.sudarshan.tictactoenew           I  menupage
2022-10-02 21:58:03.626 13019-13019 Itemname                com.sudarshan.tictactoenew           I  menupage
2022-10-02 21:58:08.837 13019-13019 Itemname                com.sudarshan.tictactoenew           I  classictictactoe
---------------------------- PROCESS ENDED (13019) for package com.sudarshan.tictactoenew ----------------------------
---------------------------- PROCESS STARTED (13341) for package com.sudarshan.tictactoenew ----------------------------
---------------------------- PROCESS ENDED (13341) for package com.sudarshan.tictactoenew ----------------------------
---------------------------- PROCESS STARTED (13430) for package com.sudarshan.tictactoenew ----------------------------
2022-10-02 21:59:31.086 13430-13430 Itemname                com.sudarshan.tictactoenew           I  menupage
2022-10-02 21:59:36.137 13430-13430 Itemname                com.sudarshan.tictactoenew           I  classictictactoe

menupage和classicticctactoe都是activity。活动打开时应播放音乐（菜单页面和 classicticctactoe） 但是当activity classictictactoe打开时没有音乐播放，音乐只在menupage activity打开时播放

//classictictactoe活动相关代码部分

Intent  intent = new Intent(ClassicTicToe.this, BackgroundSoundService.class);
        intent.putExtra("itemname","classictictactoe");
        startService(intent);

//menupage activity相关代码部分

i = new Intent(MenuPage.this, BackgroundSoundService.class);
       i.putExtra("itemname","menupage");
        startService(i);

我不明白为什么两个活动的音乐都没有播放

我在raw文件夹里有音乐文件cof.mp3和got.mp3

Answer 1

我认为你应该将

mp = null;

添加到Destroy

public void onDestroy() {
        mp.stop();
        mp.release();
        mp = null;
    }

查看这个例子了解更多信息

Answer 2

请检查：

if(mp != null) {
    mp.stop();
    mp.release();
}
mp = new MediaPlayer();

    ...
    ...
    ...

return Start_Sticky;