Не рисует на SurfaceView, android?

Question

titovnikita @titovnikita

Не рисует на SurfaceView, android?

Здравствуйте, нужна Ваша помощь.
Для решения моей задачи, мне нужно 2 SurfaceView: 1 для того чтобы брать с него и обрабатывать кадры с камеры, второй для того чтобы отрисовывать полученные данные. Так вот, при запросе Canvas функция lockCanvas возвращает null.

private SurfaceView sv;
	private SurfaceView svfd; // Surface view for drawing
	private SurfaceHolder holder;
	private SurfaceHolder holderFD; // Holder for drawing on Surface View
	private HolderCallback holderCallback;
	private Camera camera;
	...
	private Paint paint;
	
	private final PreviewCallback previewCallback;
	
	final int CAMERA_ID = 0;
	final boolean FULL_SCREEN = true;
	private int ocr_count = 0; // TODO Delete after tests
	...

	protected void onCreate(Bundle savedInstanceState) {
	    super.onCreate(savedInstanceState);
	    
	    Intent intent = getIntent();
	    mLang = intent.getStringExtra("lang");
	    requestWindowFeature(Window.FEATURE_NO_TITLE);
	    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
	        WindowManager.LayoutParams.FLAG_FULLSCREEN);
	    setContentView(R.layout.realtime);

	    sv = (SurfaceView) findViewById(R.id.surfaceView);
	    svfd = (SurfaceView) findViewById(R.id.surfaceViewForDrawing);
	    svfd.setZOrderOnTop(true);
	    holder = sv.getHolder();
	    holderFD = svfd.getHolder();

	    holderCallback = new HolderCallback(this, this);
	    holder.addCallback(holderCallback);
	    
	    handler = new RealTimeHandler(this, camera, mLang);
	    previewCallback.setHandler(handler);
	    
	    paint = new Paint();
	  }
...

 public void drawFounded(OcrDB OcrResult){
		  if(OcrResult!=null){
			  Canvas canvas = holderFD.lockCanvas(); // ВОТ ТУТ ВОЗВРАЩАЕТСЯ null
			  if (canvas == null) {
				  Log.e("Recognized", "Cannot draw onto the canvas as it's null");
			  } else { 
				  OcrResult.getWords(); 
				  OcrResult.getFoundedWordsArray("your"); // input a word to find
				  Log.e("Recognized", "else of drawFounded starting");
	            
				  if(OcrResult.getFoundedWordNum().size()>0){
				  // Draw bounding boxes around each word
				  for (int i = 0; i < OcrResult.getFoundedWordNum().size(); i++) {
					  paint.setAlpha(0xFF);
					  paint.setColor(0xFF00CCFF);
					  paint.setStyle(Style.STROKE);
					  paint.setStrokeWidth(2);
					  Rect r = OcrResult.getWordBoundingBoxes().get(OcrResult.getFoundedWordNum().get(i));
					  canvas.drawRect(r, paint);
					  Toast.makeText(this, "founded", Toast.LENGTH_SHORT).show();
					  Log.e("Recognized", "trying to draw");
				  }
				  holderFD.unlockCanvasAndPost(canvas);
				  Log.e("Recognized", "unlock canvas");
				  //sv.setZOrderOnTop(true);
				  //svfd.setZOrderOnTop(false);  // try another combination
				  }
	        }
		  }
	  }

Заранее спасибо вам за помощь.