如何在Android中的onCreate方法中拍攝照片而不是onClick？

Question

我正在拍攝一張照片。當我離開它時，它目前工作正常，但是當我嘗試更改它以使圖片嘗試以不同方法拍攝（而不是由onClick（）方法激活）時，它每次都會出錯。目前，工作代碼如下：

public class Testing123 extends Activity { 

    private SurfaceView preview=null; 
    private SurfaceHolder previewHolder=null; 
    private Camera camera=null; 
    private boolean inPreview=false; 
    private boolean cameraConfigured=false; 

    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     setContentView(R.layout.main); 
     preview = (SurfaceView)findViewById(R.id.preview); 
     previewHolder = preview.getHolder(); 
     previewHolder.addCallback(surfaceCallback); 
     previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 

     testing(); //HERE is where I am testing, but cannot get it to work. [See part 2] 
    } 

    public void onResume() { 
     super.onResume(); 
     if (camera == null) { 
      camera=Camera.open(); 
      L.m("Camera open in onResume"); 
     } 
     startPreview(); 
    } 

    public void onPause() { 
     if (inPreview) { 
      camera.stopPreview(); 
     } 
     camera.release(); 
     camera=null; 
     inPreview=false; 
     super.onPause(); 
    } 

    public boolean onCreateOptionsMenu(Menu menu) { 
     new MenuInflater(this).inflate(R.menu.options, menu); 
     return(super.onCreateOptionsMenu(menu)); 
    } 

    public boolean onOptionsItemSelected(MenuItem item) { 
     if (item.getItemId() == R.id.camera) { 
      if (inPreview) { 
       camera.takePicture(null, null, photoCallback); //THIS IS WHERE THE PHOTO IS BEING TAKEN 
       inPreview=false; 
      } 
     } 

     return(super.onOptionsItemSelected(item)); 
    } 

    private void initPreview(int width, int height) { 
     if (camera != null && previewHolder.getSurface() != null) { 
      try { 
       camera.setPreviewDisplay(previewHolder); 
      } 
      catch (Throwable t) { 
       Log.e("PreviewDemo-surfaceCallback", "Exception in setPreviewDisplay()", t); 
      } 

      if (!cameraConfigured) { 
       Camera.Parameters parameters=camera.getParameters(); 
       setCameraResolution(); //Leaving this method out for now 
       camera.setParameters(parameters); 
       cameraConfigured=true; 
      } 

     } 
    } 

    private void startPreview() { 
     camera.startPreview(); 
    } 

    SurfaceHolder.Callback surfaceCallback=new SurfaceHolder.Callback() { 
     public void surfaceCreated(SurfaceHolder holder) { 
     } 

     public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { 
      initPreview(width, height); 
      startPreview(); 
     } 

     public void surfaceDestroyed(SurfaceHolder holder) { 
     } 
    }; 

    Camera.PictureCallback photoCallback = new Camera.PictureCallback() { 
     public void onPictureTaken(byte[] data, Camera camera) { 
      //This part is no problem, I am able to write it to the file and use the data from the output of the camera 
     } 
    } 

問題是當我嘗試做一個新的呼叫，因爲你在onCreate（）方法看，所謂的測試（）;每當我打電話給測試方法，這是試圖繞過需要按下按鈕，它錯誤了。下面是測試（）代碼：

private void testing() { 
    try{ 
     cameraConfigured=true; 
     inPreview=true; 
     camera=Camera.open(); 
     Camera.Parameters parameters=camera.getParameters(); 
     setCameraResolution(); 
     camera.setParameters(parameters); 
     camera.setPreviewDisplay(previewHolder); 
     startPreview(); 
     camera.takePicture(null, null, photoCallback); //THIS IS WHERE THE PHOTO IS BEING TAKEN 
    } catch (Exception e) { 
     L.m(e.toString()); 
    } 
} 

而且它的錯誤出在那之後，具體說： 了java.lang.RuntimeException：takePicture失敗

只是重申，它需要的照片就好了，當我點擊一個圖標/按鈕這樣做，我試圖完成的是它運行該代碼，而無需點擊按鈕/圖標。我覺得這是非常簡單的東西，我想念，我似乎無法弄清楚。

Answer 1

致電testing()在SurfaceHolder.Callback#onSurfaceCreated。
:-)