如何切換手電筒模式？

Question

我想添加一個按鈕（我已經包括在我的activity_main中）到我的應用程序，它將在按下時啓動頻閃效果，並在再次按下時停止。我不關心速度，只是它重複切換flash_mode_torch和flash_mode_off，直到再次按下按鈕。

我曾嘗試：

• 通過處理器
• 創建一個單獨的類

包含處理程序，因爲有主活動無意推出沒有工作的單獨的類或者在清單中，因爲它的代碼沒有完成，因爲我想問一下它是如何以最簡單的方式完成的。

Answer 1

StrobeLightConfig.java

import android.app.Activity; 
    import android.content.Intent; 
    import android.hardware.Camera; 
    import android.os.Bundle; 
    import android.os.Handler; 
    import android.view.View; 
    import android.widget.ImageButton; 
    import android.widget.SeekBar; 
    import android.widget.SeekBar.OnSeekBarChangeListener; 

    public class StrobeLightConfig extends Activity { 

     boolean check = false; 

     Camera sandy; 
     StrobeRunner runner; 
     Thread bw; 
     ImageButton btnClick; 

     public final Handler mHandler = new Handler(); 

     public final Runnable mShowToastRunnable = new Runnable() { 
      public void run() { 

      } 
     }; 

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

      btnClick = (ImageButton) findViewById(R.id.btnSwitch); 


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

      if (runner.isRunning) { 

      } else { 
       try { 
        sandy = Camera.open(); 

        if (sandy == null) { 
         return; 
        } 

        sandy.release(); 
       } catch (RuntimeException ex) { 
        return; 
       } 
      } 

      bw = new Thread(runner); 
      bw.start(); 

      btnClick.setOnClickListener(new View.OnClickListener() { 

       @Override 
       public void onClick(View arg0) { 
        // TODO Auto-generated method stub 
        if (check) { 
         bw = new Thread(runner); 
         bw.start(); 
         check = false; 
        } else { 
         check = true; 
         runner.requestStop = true; 
        }    
       } 
      }); 

      final SeekBar skbar = (SeekBar) findViewById(R.id.SeekBar01); 
      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 = 101 - progress; 
        runner.delayoff = 101 - progress; 

       } 
      }); 

     } 

     @Override 
     protected void onStop() { 
    //  runner.requestStop = true; 

      super.onStop(); 
     } 

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

      Intent startMain = new Intent(Intent.ACTION_MAIN); 
      startMain.addCategory(Intent.CATEGORY_HOME); 
      startActivity(startMain); 

     } 

    } 

StrobeRunner.java

import android.hardware.Camera; 

public class StrobeRunner implements Runnable { 

    protected StrobeRunner() 
    { 

    } 

    public static StrobeRunner getInstance() 
    { 
     return (instance == null ? instance = new StrobeRunner() : instance); 
    } 

    private static StrobeRunner instance; 


    public volatile boolean requestStop = false; 
    public volatile boolean isRunning = false; 
    public volatile int delay = 10; 
    public volatile int delayoff = 500; 
    public volatile StrobeLightConfig controller; 
    public volatile String errorMessage = ""; 

    @Override 
    public void run() { 
     if(isRunning) 
      return; 

     requestStop=false; 
     isRunning = true; 

     Camera cam = Camera.open(); 

     Camera.Parameters pon = cam.getParameters(), poff = cam.getParameters(); 

     pon.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH); 
     poff.setFlashMode(Camera.Parameters.FLASH_MODE_OFF); 

     while(!requestStop) 
     { 
      try{ 
       cam.setParameters(pon); 
       Thread.sleep(delay); 
       cam.setParameters(poff); 
       Thread.sleep(delayoff); 
      } 
      catch(InterruptedException ex) 
      { 

      } 
      catch(RuntimeException ex) 
      { 
       requestStop = true; 
       errorMessage = "Error setting camera flash status. Your device may be unsupported."; 
      } 
     } 

     cam.release(); 

     isRunning = false; 
     requestStop=false; 

     controller.mHandler.post(controller.mShowToastRunnable); 
    } 

} 

main.xml中

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/TableLayout1" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    > 

    <SeekBar 
     android:id="@+id/SeekBar01" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:max="100" 
     android:paddingLeft="5dp" 
     android:paddingRight="5dp" 
     android:progress="0" 
     android:layout_alignParentTop="true" 
     > 
    </SeekBar> 

    <ImageButton 
     android:id="@+id/btnSwitch" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:src="@drawable/w_led_on" 
     android:layout_centerVertical="true" 
     android:layout_centerHorizontal="true" 
     android:layout_marginTop="50dp"/> 

</RelativeLayout>