Memory problems with big controls

[Steve McLellan]

Hi,

I thought I'd come up with a cunning plan to display a really large picture
(I don't want to use PictureBox for various reasons):
- Create a Panel the same size as the picture
- Use some scroll bars to set the .Top and .Left of the panel
- Use a paint handler to do some fancy stuff with the rectangle I get
passed by Invalidate

This works great until the picture gets too big (it breaks at about 20000 *
20000 pixels). My reasoning for doing this was that I'd only need to use
enough memory to hold the visible portion of the image, since I'm drawing
directly onto the Graphics object given by OnPaint. It appears, however,
that resizing the panel is causing Windows to try to generate an
extraordinarily large buffer and is failing miserably to do so. This method
also makes worknig out where the scrollbars should be fairly trivial.

Is there a way to stop Windows trying to initialise an enormous buffer it
doesn't need, or am I going to have to do this more manually and recalculate
the area of the image I need to display based on where the scroll bars are?

Thanks,

Steve