Canvas.Scroll - what's the point?

General
1

I’m scrolling PDF pages of sheet music so the eyes can follow the music. Examining the Canvas.Scroll method, I find that you must calculate the new position of the picture before calling the Scroll method. Then the Paint event draws the picture in the shifted position. I’m calculating the new position and shift value in a timer.

I couldn’t understand why using the Scroll method was any different than just calling Invalidate because the Paint method uses the properties you’ve already calculated. It amounts to using either of the following lines of code at the end of the Timer event:

myCanvas.Invalidate
myCanvas.Scroll Xshift, 0

My tests show they both execute at equal speeds. Am I missing something here? What’s the point?

2

Scroll is for when you’ve placed controls on the canvas.

3

Thanks. That makes sense.