Armando Serrano Lombillo wrote:
canvas.PrepareDC(dc)
"Call this function to prepare the device context for drawing a scrolled image",
exactly. If your image is on a scrolled window, then you have two coordinate systems -- the "virtual" one and the actual pixel coords of the window in its current position. PrepareDC() sets up the DC to deal with that, so you can draw in the virtual coordinate system.
It may be that you've tested in only when the image wasn't scrolled, so it didn't make a difference then.
-Chris
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Christopher Barker, Ph.D.
Oceanographer
Emergency Response Division
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