機器人集搜索條初次和切換播放按鈕暫停時，音樂結束

Question

我設計一個從無到有的媒體播放器等什麼我正陷在是，當歌曲結束播放我想搜索條設置爲初始值 我知道這可以用

seekBar.setProgress（0） 做，但這個不跟我合作，我想播放按鈕切換到暫停按鈕，如果用戶播放的歌曲再次比歌可以正常播放 這裏是我的媒體播放器的代碼，並希望你能告訴我這是什麼邏輯，以及如何把它

public class MusicPlayerActivity extends AppCompatActivity implements Runnable, 
     SeekBar.OnSeekBarChangeListener { 
ImageView playpause; 
SeekBar seekBar; 
MediaPlayer mp = null; 
int len = 0; 
boolean isPlaying = false; 


public MusicPlayerActivity() throws IOException { 
} 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_music_player); 
    String url = getIntent().getExtras().getString("musicurl"); 
    playpause = (ImageView)findViewById(R.id.imageView); 
    seekBar = (SeekBar)findViewById(R.id.seekBar); 
    playpause.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 

      if(!isPlaying){ 
       playpause.setImageResource(R.drawable.pause); 
       mp.pause(); 
       len = mp.getCurrentPosition(); 
       seekBar.setEnabled(false); 


      }else{ 
       playpause.setImageResource(R.drawable.play); 
       mp.seekTo(len); 
       mp.start(); 
       seekBar.setEnabled(true); 

      } 
      isPlaying = !isPlaying; 



     } 
    }); 

    mp = new MediaPlayer(); 
    try { 
     mp.setDataSource(url); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    try { 
     mp.prepare(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    //if(mp.isPlaying()) mp.stop(); mp.release(); 
    mp.start(); 
    seekBar.setMax(mp.getDuration()); 
    new Thread(this).start(); 
    // Toast.makeText(this, mp.getDuration(), Toast.LENGTH_SHORT).show(); 


} 

//if(mp.isPlaying()){} 
@Override 
public void onProgressChanged(SeekBar seekBar, int progress, 
           boolean fromUser) { 
    try { 
     if (mp.isPlaying() || mp != null) { 
      if (fromUser) 
       mp.seekTo(progress); 
     } else if (mp == null) { 
      Toast.makeText(getApplicationContext(), "Media is not running", 
        Toast.LENGTH_SHORT).show(); 
      seekBar.setProgress(0); 
     } 
    } catch (Exception e) { 
     Log.e("seek bar", "" + e); 
     seekBar.setEnabled(false); 

    } 
} 

@Override 
public void onStartTrackingTouch(SeekBar seekBar) { 

} 

@Override 
public void onStopTrackingTouch(SeekBar seekBar) { 

} 

public void run() { 
    int currentPosition = mp.getCurrentPosition(); 
    int total = mp.getDuration(); 

    while (mp != null && currentPosition < total) { 
     try { 
      Thread.sleep(1000); 
      currentPosition = mp.getCurrentPosition(); 
     } catch (InterruptedException e) { 
      return; 
     } catch (Exception e) { 
      return; 
     } 
     seekBar.setProgress(currentPosition); 
    } 
} 
@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    switch (item.getItemId()) { 
     case android.R.id.home: 
      mp.stop(); 
      startActivity(new Intent(this,MainActivity.class)); 
      break; 
    } 
    return true; 
} 
@Override 
public void onBackPressed() { 
    Intent mainActivity = new Intent(Intent.ACTION_MAIN); 
    mainActivity.addCategory(Intent.CATEGORY_HOME); 
    mainActivity.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
    startActivity(mainActivity); 
} 

在 onCreate

}

Answer 1

您沒有設置監聽器：seekbar.setOnSeekBarChangeListener(this)

Answer 2

添加seekbar.setOnSeekBarChangeListener(this);否則onProgressChanged()不會被調用。

要重置進度欄看看下面的辦法：

上的媒體播放器實例設置OnCompletionListener。當媒體文件完成播放，您可以開展OnCompletion(MediaPlayer mp)回調函數所需的操作。

mp.start()之前添加以下代碼段應爲你工作。

mp.setOnCompletionListener(new OnCompletionListener() { 

      @Override 
      public void onCompletion(MediaPlayer mp) { 
       seekBar.setProgress(0); // sets seekbar to initial position. 
       toggleViews();//implement this function to toggle your play/pause button 

      } 

     });