無法停止線程onBackPressed

Question

我有一個名爲runner的線程。我想停止這個線程onBackPressed，但這沒有發生。下面是代碼：

public class StrobeLightConfig extends Activity { 

    Camera cam; 
    StrobeRunner runner; 
    Thread bw; 
    CheckBox strobe; 
    private boolean isFlashOn; 
    private boolean hasFlash; 
    private Parameters params; 
    private MediaPlayer mp; 
    VerticalSeekBar skbar, skbaroff; 
    ToggleButton togglebutton; 

    public final Handler mHandler = new Handler(); 

    public final Runnable mShowToastRunnable = new Runnable() { 
     public void run() { 
      showMessage(); 
     } 
    }; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     skbar = (VerticalSeekBar) findViewById(R.id.SeekBar01); 
     strobe = (CheckBox) findViewById(R.id.checkBox1); 
     togglebutton = (ToggleButton) findViewById(R.id.ToggleButton01); 
     skbaroff = (VerticalSeekBar) findViewById(R.id.SeekBar02); 

     hasFlash = getApplicationContext().getPackageManager() 
       .hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH); 

     turnOnFlash(); 

     strobe.setOnCheckedChangeListener(new OnCheckedChangeListener() { 

      @Override 
      public void onCheckedChanged(CompoundButton buttonView, 
        boolean isChecked) { 

       if (buttonView.isChecked()) { 
        cam.release(); 
        Toast.makeText(getApplicationContext(), "Released 1", 0) 
          .show(); 
       } else { 
        cam.release(); 
        Toast.makeText(getApplicationContext(), "Released 2", 0) 
          .show(); 
       } 

      } 
     }); 

     runner = StrobeRunner.getInstance(); 
     runner.controller = this; 

     if (runner.isRunning) { 

     } else { 
      try { 

       if (cam == null) { 
       cam = Camera.open(); 
       } 


      } catch (RuntimeException ex) { 
       togglebutton.setEnabled(false); 
       TextView t = (TextView) findViewById(R.id.TextViewHW2); 
       t.setText(R.string.nocamera); 
       Toast.makeText(getApplicationContext(), 
         "Error connecting to camera flash.", Toast.LENGTH_LONG) 
         .show(); 
       return; 
      } 
     } 

     togglebutton.setOnClickListener(new OnClickListener() { 
      public void onClick(View v) { 
       // Perform action on clicks 
       if (strobe.isChecked()) { 
        if (togglebutton.isChecked()) { 
         turnOnStrobe(); 
        } else { 
         turnOffStrobe(); 
        } 
       } else { 

        if (isFlashOn) { 
         // turn off flash 
         turnOffFlash(); 
        } else { 
    ----------------- runner.requeststop working here--------------------- 
         turnOnFlash(); 
        } 

       } 

      } 
     }); 


     skbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() { 

      @Override 
      public void onStopTrackingTouch(SeekBar seekBar) { 
       // TODO Auto-generated method stub 

      } 

      @Override 
      public void onStartTrackingTouch(SeekBar seekBar) { 
       // TODO Auto-generated method stub 

      } 

      @Override 
      public void onProgressChanged(SeekBar seekBar, int progress, 
        boolean fromUser) { 
       runner.delay = progress; 

      } 
     }); 


     skbaroff.setOnSeekBarChangeListener(new OnSeekBarChangeListener() { 

      @Override 
      public void onStopTrackingTouch(SeekBar seekBar) { 
       // TODO Auto-generated method stub 

      } 

      @Override 
      public void onStartTrackingTouch(SeekBar seekBar) { 
       // TODO Auto-generated method stub 

      } 

      @Override 
      public void onProgressChanged(SeekBar seekBar, int progress, 
        boolean fromUser) { 
       runner.delayoff = progress; 

      } 
     }); 



    } 

    private void getCamera() { 
     if (cam == null) { 
      try { 
       cam = Camera.open(); 
       params = cam.getParameters(); 
      } catch (RuntimeException e) { 
       Log.e("Camera Error. Failed to Open. Error: ", e.getMessage()); 
      } 
     } 
    } 

    /* 
    * Turning On flash 
    */ 
    private void turnOnFlash() { 
     if (!isFlashOn) { 
      togglebutton.setChecked(true); 
      cam = Camera.open(); 
      params = cam.getParameters(); 
      params.setFlashMode(Parameters.FLASH_MODE_TORCH); 
      cam.setParameters(params); 
      cam.startPreview(); 
      isFlashOn = true; 
      strobe.setEnabled(false); 
     } 

    } 

    private void turnOffFlash() { 
     if (isFlashOn) { 
      togglebutton.setChecked(false); 
      params = cam.getParameters(); 
      params.setFlashMode(Parameters.FLASH_MODE_OFF); 
      cam.setParameters(params); 
      cam.stopPreview(); 
      cam.release(); 
      isFlashOn = false; 
      strobe.setEnabled(true); 

     } 
    } 

    private void turnOnStrobe() { 
     if (!isFlashOn) { 
      strobe.setEnabled(false); 
      bw = new Thread(runner); 
      bw.start(); 
     } 

    } 

    private void turnOffStrobe() { 
     if (isFlashOn) { 

       runner.requestStop = true; 
       strobe.setEnabled(true); 

     } 
    } 

    @Override 
    protected void onDestroy() { 
     super.onDestroy(); 
    } 

    @Override 
    protected void onPause() { 
     super.onPause(); 

    } 

    @Override 
    protected void onRestart() { 
     super.onRestart(); 
    } 

    public void showMessage() { 
     String err = runner.errorMessage; 
     runner.errorMessage = ""; 
     if (!err.equals("")) { 
      Context context = getApplicationContext(); 
      int duration = Toast.LENGTH_SHORT; 

      Toast toast = Toast.makeText(context, err, duration); 
      toast.show(); 
     } 

     ToggleButton togglebutton = (ToggleButton) findViewById(R.id.ToggleButton01); 
     togglebutton.setChecked(false); 
    } 

    @Override 
    public void onBackPressed() { 
     // TODO Auto-generated method stub 
     super.onBackPressed(); 

     if (strobe.isChecked()) { 
      turnOffStrobe(); 
     } else { 

      if (isFlashOn) { 
       ----------------- runner.requeststop needs to work here---------------------  
       turnOffFlash(); 
       finish(); 
       moveTaskToBack(true); 
      } 
     } 
    } 
} 

但是如果我寫

runner.requestStop = true; 
strobe.setEnabled(true); 

在TurnoffStrobe的在OnCreate（不onBackPressed），其工作的地方。我能做些什麼runner.requeststop在外面工作創建。？

Answer 1

嘗試 your_thread.isInterrupted（）; insideBackpress（）