Is there a way to stop all MediaPlayers?

问题:

I am currently developing my first Android application by reading Dev Documentation at Android official website. What I am trying to accomplish is to play some ring sounds. A section from my code is:

import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;

public class PlayRingSounds extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
}

public void PlayRingFile(View view) {       
  switch (view.getId()) {
    case R.id.Button01:
      MediaPlayer mp1 = MediaPlayer.create(this.getApplicationContext(), R.raw.aaa);
      mp1.start();
      break;
    case R.id.Button02:
      MediaPlayer mp2 = MediaPlayer.create(this.getApplicationContext(), R.raw.bbb);
      mp2.start();
      break;        
  }
}   
}

The problem is when I click the 2nd button while "aaa" (sound file from 1st button) is playing, "bbb" also starts playing at the same time. Is there a way to stop "aaa" before "bbb" plays, or is there a way to stop all media players?

Update 12/30/2009 - New code is:

   case R.id.Button01:
       if (mp2.isPlaying())
       {
           mp2.stop();
           mp2.release();
       }
       mp1.reset();
       mp1.prepare();
       mp1.start();
       break;
   case R.id.Button02:
       if (mp1.isPlaying())
       {
           mp1.stop();
           mp1.release();
       }
       mp2.reset();
       mp2.prepare();
       mp2.start();
       break;

mp1.prepare() and mp2.prepare() give IOException error.

回答1:

Please note: This is not the best way to do this, this is very sloppy, this is just an idea

public void PlayRingFile(View view) {       
  switch (view.getId()) {
   case R.id.Button01:
    if (mp2.isPlaying()) {
       mp2.stop();    // stops the object from playing
       mp2.release(); // always a good practice to release the resource when done
     }
    MediaPlayer mp1 = MediaPlayer.create(this.getApplicationContext(), R.raw.aaa);
    mp1.start();
    break;
   case R.id.Button02:
    if (mp1.isPlaying()) {
       mp1.stop();    // stops the object from playing
       mp1.release(); // always a good practice to release the resource
     }
    MediaPlayer mp2 = MediaPlayer.create(this.getApplicationContext(), R.raw.bbb);
    mp2.start();
    break;        
 }
}

As I said, this isn't the best solution especially if you add more buttons then you would have to check every instance of MediaPlayer and there must be better ways of doing this.

My suggestions are to try to find a way to loop through all MediaPlayer's to see if they are open and if so, release the resource and stop playing or maybe a way to stop all MediaPlayer's from playing in general?

I will continue to look for other ways in the meantime, hope this points you in the right direction.

EDIT (12/30/09):

case R.id.Button01:
   if (mp2.isPlaying())  {
       mp2.stop();
       mp2.release();
   }
   mp1.reset();
   createMPlayer1(); // used to re-initialze the mediaplayer for reuse since resources were released.
   mp1.prepare();
   mp1.start();
   break;
case R.id.Button02:
   if (mp1.isPlaying()) {
       mp1.stop();
       mp1.release();
   }
   mp2.reset();
   createMPlayer2();
   mp2.prepare();
   mp2.start();
   break;

public void createMPlayer1() {
   MediaPlayer mp1 = MediaPlayer.create(this.getApplicationContext(), R.raw.aaa);
}

public void createMPlayer2() {
   MediaPlayer mp2 = MediaPlayer.create(this.getApplicationContext(), R.raw.bbb);
}

I think the IOException could be called when trying to access the file again after we have renoved the resouce. I added two methods to create the separate raw files since I believe the exception occurs when the resources are released. You can either re-initialized the MediaPlayer's or try to discard releasing the resource.