Clearing canvas with Canvas.drawColor()
- by strangeInAStrangerLand
I'm attempting to change the background image of a custom View with some success. The image will change but the problem is that I still see traces of the old image. When I attempt to clear the canvas before drawing the new image, it doesn't appear to work. I create a bitmap to store the image. When changing the image, I call Canvas.drawColor() before drawing the new image but the old image persists. I've tried drawColor(0), drawColor(Color.BLACK), c.drawColor(0, PorterDuff.Mode.CLEAR), and none of the above works. As such, I had to post this for review from more experienced minds than mine.
The actual code is as follows:
private int bgnd;
private boolean switching;
public void setBgnd(int incoming){
switching = true;
switch (incoming){
case R.drawable.image1:
bgnd = incoming;
this.invalidate();
break;
case R.drawable.image2:
bgnd = incoming;
this.invalidate();
break;
}
}
protected void onDraw(Canvas c){
if(switching == true){
Bitmap b = BitmapFactory.decodeResource(getResources(), bgnd);
c.drawColor(0, PorterDuff.Mode.CLEAR);
c.drawBitmap(b, 0, 0, null);
switching = false;
}else{
Bitmap b = BitmapFactory.decodeResource(getResources(), bgnd);
c.drawBitmap(b, 0, 0, null);
}
}
