Question

Can someone explain what the rect does in: canvas.drawBitmap(bmp,scr ,dst ,null);
Because I have tried and tried to make any sense of this but I simply don’t understand what the two rectangles does.

My goal is to display a portion the bitmap instead of the whole image.

//Simon

Answer 1

The Android documentation seems to explain this method quite well.

drawBitmap Documenation

From reading the documentation it appears you can do what you want by specifying a source Rect, which will be the rectangle(subset) from the original bitmap, and it will then be translated into the dest Rectangle.

Bitmap picture; //Assume this is a 1024x768 image and has been initialized.

@Override
public void onDraw(Canvas canvas){
    //To Draw only the top left corner of the image
    Rect src = new Rect(0,0,512,368);

    Rect dest = new Rect(0,0,512,368);

    canvas.drawBitmap(picture, src, dest, null);
}