通过删除上一个在画布上设置位图的新位置

Question

I have this code:

protected void onDraw(Canvas canvas) {
    // TODO Auto-generated method stub
    super.onDraw(canvas);
    canvas.drawColor(Color.WHITE);
    canvas.drawBitmap(ball, (canvas.getWidth()/2), 0, null); 

and it draw bitmap on screen but if i want to set new position it draw new one, how can i draw a new one and erase previous one. I'd like to set new position of bitmap on canvas.

Answer 1

首先绘制颜色会全部擦除，然后以新位置绘制位图。