Not able to check Android Service Issue

问题

All I want to do is simply control background music in my app through a service so I am able to start it and stop it from any activity.

I have everything set up perfectly when I tell the service to Toast when it is started and destroyed but as soon as I put the media play-in in there instead It starts fine and starts playing the music but as soon as a click a button to stop the service I get an error and a force close.

Can anyone suggest what I am doing wrong?

Here is my code:

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

public class MyService extends Service {

private MediaPlayer player;

@Override    
public IBinder onBind(Intent intent) {
returnnull;
}

@Override    
publicvoid onCreate() { 
super.onCreate(); 
Toast.makeText(this, "Service Started", Toast.LENGTH_SHORT).show();
MediaPlayer player = MediaPlayer.create(MyService.this, R.raw.oceanwavestest);
player.start();
player.setLooping(true);

}

   @Override    
   publicvoid onDestroy() {
   super.onDestroy();
   player.stop();
   Toast.makeText(this, "Service Stopped", Toast.LENGTH_SHORT).show();
   } 
}

回答1:

There are a few things that I see in your code that I would check out if I were in your position.

You are trying to call "stop" on a member MediaPlayer object "player" in your onDestroy, but in your onCreate you create a MediaPlayer object "player" with your line of code

"MediaPlayer player = MediaPlayer.create(MyService.this, R.raw.oceanwavestest);"

which i believe creates a player object that you will loose scope of outside of the function.

The 1 line fix for this code is to just use "player = MediaPlayer.create(MyService.this, R.raw.oceanwavestest);", this way the member variable is used rather than a local variable

If this were my code I would change the member variable to be called something like m_player or mPlayer so that you know it is a member variable in your code.