如何停止运行在UIThread上运行

我有RunnableUIThread更新SeekBar而MediaPlayer正在播放。然而，当我切换到另一个活动时，我的应用程序崩溃，异常导致Runnable即使在MediaPlayer被销毁之后也会一直保留。如何停止运行在UIThread上运行

这是我的代码：

public class Guide extends AppCompatActivity implements MediaPlayer.OnPreparedListener { 

    Button back; 
    private MediaPlayer m_audio_player; 
    private Handler m_handler_seek_bar = new Handler(); 
    private SeekBar m_seek_bar; 
    private Runnable m_seek_bar_runnable; 

    private void set_up_audio(){ 
     m_audio_player = MediaPlayer.create(this, g_audio[NativeLib.get_active_landmark()]); 
     m_audio_player.setOnPreparedListener(this); 
    } 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_guide); 
     implement_back_button(); 
     set_up_audio(); 
    } 

    @Override 
    protected void onStart() { 
     super.onStart(); 
     set_up_seek_bar(); 
    } 

    private void set_up_seek_bar() { 
     m_seek_bar = (SeekBar) findViewById(R.id.seek_bar); 
     m_seek_bar.setMax(m_audio_player.getDuration()); 
     m_seek_bar_runnable = new Runnable() { 
      @Override 
      public void run() { 
       if(m_audio_player != null){ 
        m_seek_bar.setProgress(m_audio_player.getCurrentPosition()); 
       } 
       m_handler_seek_bar.postDelayed(this, 1000); 
      } 
     }; 
     // update Seekbar on UI thread 
     Guide.this.runOnUiThread(m_seek_bar_runnable); 
     m_seek_bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() { 
      @Override 
      public void onStopTrackingTouch(SeekBar seekBar) { } 
      @Override 
      public void onStartTrackingTouch(SeekBar seekBar) {} 
      @Override 
      public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) { 
       if(m_audio_player != null && fromUser){ 
        m_audio_player.seekTo(progress); 
       } 
      } 
     }); 
    } 

    @Override 
    protected void onStop() { 
     if (debug_mode) Log.d(TAG, "onStop"); 
     if (m_audio_player.isPlaying()) { 
      m_audio_player.stop(); 
     } 
     m_audio_player.release(); 
     super.onStop(); 
     findViewById(R.id.activity_guide).removeCallbacks(m_seek_bar_runnable); 
    } 

    // return button 
    private void implement_back_button() { 
     final Intent intent = new Intent(/* pointing at some other activity */); 
     back = (Button) findViewById(R.id.back_button); 
     back.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       startActivity(intent); 
      } 
     }); 
    } 
}

来源

2017-04-21 Marinos K

您需要使用：

m_handler_seek_bar.removeCallbacks(m_seek_bar_runnable);

从handler

移除可运行

@Override 
protected void onStop() { 
    if (debug_mode) Log.d(TAG, "onStop"); 
    if (m_audio_player.isPlaying()) { 
     m_audio_player.stop(); 
    } 
    m_audio_player.release(); 
    m_handler_seek_bar.removeCallbacks(m_seek_bar_runnable); 
    super.onStop(); 
}

或者，您可以覆盖该活动的onPause()方法：

@Override 
protected void onPause() { 
    m_handler_seek_bar.removeCallbacks(m_seek_bar_runnable); 
    super.onPause(); 
}

来源

2017-04-21 17:38:17 rafsanahmad007

从处理程序中的onStop删除所有回调使用handler.removeCallbacks

来源

2017-04-21 17:36:28

如何停止运行在UIThread上运行

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