媒體播放器停止後不啓動

Question

下面是我的媒體播放器代碼。我停止後它不會重新開始。如何解決這個問題？即使我在調用start方法之前調用了prepare方法。另外爲什麼即使退出程序後音樂也不會播放。請指教。

public class MainActivity extends Activity { 

Button play,pause,stop; 
CheckBox c1,c2,c3; 
MediaPlayer song1,song2,song3; 
AlertDialog.Builder builder; 

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

    play=(Button)findViewById(R.id.button1); 
    pause=(Button)findViewById(R.id.button2); 
    stop=(Button)findViewById(R.id.button3); 

    c1=(CheckBox)findViewById(R.id.checkBox1); 
    c2=(CheckBox)findViewById(R.id.checkBox2); 
    c3=(CheckBox)findViewById(R.id.checkBox3); 

    song1=MediaPlayer.create(this, R.raw.finalcountdown); 
    song2=MediaPlayer.create(this, R.raw.invincible); 
    song3=MediaPlayer.create(this, R.raw.somewhereibelong); 

    builder=new AlertDialog.Builder(this); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

public void start(View view) throws IllegalStateException, IOException 
{ 
    if(c1.isChecked()) 
    { 
     if(!song1.isPlaying()) 
     { 
      song1.prepare(); 
      song1.start(); 
     } 
     else{ 
      song1.start(); 
     } 
    } 
    if(c2.isChecked()) 
    { 
     if(!song2.isPlaying()) 
     { 
      song2.prepare(); 
      song2.start(); 
     } 
     else{ 
      song2.start(); 
     } 
    } 
    if(c3.isChecked()) 
    { 
     if(!song3.isPlaying()) 
     { 
      song3.prepare(); 
      song3.start(); 
     } 
     else{ 
      song3.start(); 
     } 
    } 
    else{ 
     builder.setMessage("Please mark a checkbox"); 
    } 
} 

public void stop(View view) 
{ 
    if(c1.isChecked()) 
     song1.stop(); 
    else if (c2.isChecked()) 
     song2.stop(); 
    else if (c3.isChecked()) 
     song3.stop(); 
    else 
     builder.setMessage("Error message "); 
} 

public void pause(View view) 
{ 
    if(c1.isChecked()) 
    { 
     song1.pause(); 
    } 
    else if(c2.isChecked()) 
    { 
     song2.pause(); 
    } 
    else if(c3.isChecked()) 
    { 
     song3.pause(); 
    } 
    else 
     builder.setMessage("error message"); 
} 

} 

Answer 1

您需要將song1.release（）和其他歌曲的發佈方法放在stop方法中。請參閱媒體播放器的生命週期以獲取更多信息。 http://developer.android.com/reference/android/media/MediaPlayer.html

Answer 2

你必須釋放播放器的OnPause或OnDestroy方法。

@Override 
public void onDestroy() { 
    if(c1!= null)c1.release(); 
    else if (c2!= null)c2.release(); 
    else if (c3!= null)c3.release(); 
    else 
     //something 
}