Creating a Transparent "Canvas" Over Form
Posted on 2003-03-01
I am trying to create an application that has a transparent "canvas" (or "layer") over a WebBrowser control. While being able to see the contents of the WebBrowser control, users could scrible on this canvas.
It would be as if the web page being displayed was the background image to a PictureBox control. Using GDI API calls, the user could then draw on the control to highlight important information.
I've tried a PictureBox. While I can get it be transparent (which makes me wonder, since MSDN says I can't do that), the PictureBox.Refresh and PictureBox.Cls will destroy the transparency. For one reason or another, I can not get it transparent again after calling either one of those.
I've tried creating a custom control, but I don't seem to have access to a hWnd or a hDC to use for drawing.
Can I create a transparent control that will allow me to use the API drawing calls to scrible on it, while the controls under it are still visible?
Many thanks for any help!
I only have 150 available to me at the moment, but if I can get this figured out by Monday I will gladly up the point value when I have more!