Nothing Shows Up on Canvas from SurfaceHolder . lockCanvas() [Android]

Question

I'm trying to draw on the canvas that is returned from the surface holder's .lockCanvas() function but the canvas that is rendered is simply white.

My MySurface extends SurfaceView and implements SurfaceHolder The constructor:

MySurface(Context context){
            super(context);
            surfaceHolder = getHolder();
            surfaceHolder.addCallback(this);
            displayThread = new MyDisplayThread(surfaceHolder);
        }

My surfaceCreated() override

public void surfaceCreated(SurfaceHolder sH){
            displayThread.start();
        }

My surfaceDestroyed() override

public void surfaceDestroyed(SurfaceHolder sH){
            boolean reset = true;
            while(reset){
                try{
                    displayThread.join();
                    reset = false;
                }catch (InterruptedException e){}
            }
        }

And the thread that I use for drawing: the class variables are:

SurfaceHolder surfaceHolder,
Paint paint,
boolean isRunning,
Canvas canvas = null


 class MyDisplayThread extends Thread {

        MyDisplayThread(SurfaceHolder sH){
            surfaceHolder = sH;
            isRunning = true;
            paint = new Paint();
        }

        @Override
        public void run(){
            while(isRunning){
                canvas = surfaceHolder.lockCanvas();
                try{
                    myDraw();
                }finally {
                    if(canvas != null) surfaceHolder.unlockCanvasAndPost(canvas);
                }
            }
        }

        public void myDraw(){
            paint.setARGB(255,152,54,12);
            canvas.drawText("RSFDS",100,100,paint);
            canvas.drawRect(120,150,300,300,paint);
            paint.setARGB(255,255,255,255);
        }
    }

Answer 1

Try the following (these have worked for me in the past):

Put setWillNotDraw(false); inside surfaceCreated

Call postInvalidate(); on your SurfaceHolder object before drawing each frame.

Answer 2

You need to call getHolder() again after surfaceCreated() is called. That should fix your problem.

@Override
public void surfaceCreated(SurfaceHolder holder) {
    surfaceHolder = getHolder();
}