How to redraw SurfaceView using invalidate() metod?

问题

I have a class GameBoard which extends SurfaceView. Inside I have an OnDraw method:

@Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        int size  = getWidth()/8;
        canvasSize = size;
        pawnBitmap[0] = bigPawn;
        pawnBitmap[1] = smallPawn;
        float left_distance;
        float top_distance;
        for(int j = 0; j < 10; j++){
            for (int i =0; i < 4; i++){
                left_distance = i*size+(float)50;
                top_distance = j*size+(float)10;
                canvas.drawBitmap(pawnBitmap[0], left_distance, top_distance, paint);
                canvas.drawBitmap(pawnBitmap[1], 6*size+i*30+(float)10, top_distance+30, paint);
            }
        }

    }

pawnBoard, bigPawn and smallPawn are public in this class and they are like:

public BitmapFactory myBitmapFactory = new BitmapFactory();

public  Bitmap[] pawnBitmap = new Bitmap[2];
public Bitmap bigPawn =  Bitmap.createScaledBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.game_button_2), 90, 90, false);
public Bitmap smallPawn = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.game_button_2), 30, 30, false);

I have also a second method in which I'm changing the image of bigPawn and smallPawn :

public void setBitmaps(Bitmap one, Bitmap two){
        this.paint = new Paint();
        this.bigPawn = one;
        this.smallPawn = two;
        this.tmp=4;
        invalidate();

    }

But after calling this method inside another (inside another class), the images are not changing. I checked using the tmp variable if setBitmaps() method really changes the images, and this is correct. But the invalidate function doesn't work. Why? Here is how I'm calling the setBitmaps method:

public void savePermutation(View view){

        Bitmap tmpBitmap1 = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.blue), 230, 230, false);
        Bitmap tmpBitmap2 = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.blue), 100, 100, false);
        myGameBoard.setBitmaps(tmpBitmap1, tmpBitmap2);


    }

I was looking for the solution, but none of this which I found was helpfull.

回答1:

Override surfaceCreated(). Then add this line:

setWillNotDraw(false);

来源：https://stackoverflow.com/questions/14676741/how-to-redraw-surfaceview-using-invalidate-metod