How to read pixels on canvas or panel?

[positrom2]

Hello,
I have a vertical line (used as a cursor) drawn on a canvas. It can be moved sideways across a previously drawn colored curve to select part of the curve. In order to have a single cursor line the preceeding cursor line is given the background color. Thereby unfortunately the curve points also are erased but I would like to preserve them. I am sure there is a function to read out the points on a panel (canvas) on a vertical (or horizontal) line, but I have no idea how to do it. Help is appreciated.
Regards, positrom2

 

[Erel]

You can use Canvas.Bitmap.GetPixel to find the value of a pixel.

I guess that there are simpler solutions. You can either draw the curve again with the background color or you can use several layers.

 

[positrom2]

Thanks,
yes, adding a separate layer for the cursors works fine.
positrom2