Bitmap with a scroll bar

Hi

I have a problem I can't think through.
If there are one bitmap and one scroll bar, how can I change the bitmap color by moving the scroll bar.

For example, the scroll bar Max.length = 255.

At the beginning, the scrollbar is on the left and the position = 0, bitmap color is white, as I move the scrollbar the color of the bitmap changes and becomes to black until the scrollbar is on the right side and position = 255. Any one who knows the idea can you please write a sample code. I wish it is clear :p, Thank you!!

Well first in most cases

0 == BLACK

255 == WHITE

but

Code:

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Find scroll bar pos

Convert to a colour  (ie COLORREF  Black=RGB(0,0,0); this will be based on the 'scrollpos' ie Current_Colour = RGB(scrollpos,scrollpos,scrollpos);

//You will have a HDC with the client area in it.

Just find the area to paint (GetClientRect() )

Create a brush with the correct colour

use FillRect() to colour it in

call for a paint

Clean up the GDI resources created

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