I have a very simple vb.net example, where I am using GDI+ to draw a simple pattern directly on the form... just a checkerboard of black/white squares. That bit works fine. See the attached screenshot.
However, if I try to save the form as an image file, the pattern I drew is not included (again, see screenshot). The pattern does not get erased off the form, but it is not included in the image file.
If the form is "refreshed", or another window covers up the pattern, then it is erased... that part I understand. But I don't know why the pattern does not show up on the image saved to a file.
I have included the Form1.vb file, which has all the code... to try it just create a new form with 3 buttons, and copy/paste the contents of my Form1.vb into yours.