I have an MDI program that handles several types of image files. When
opened each type of image file is converted to a DIB for viewing. I do
not allow for New File, I only allow for opening an existing file. (they
are created elsewhere.) I want to be able to
display multiple file extensions on the Open File dialog box. I have
tried creating multiple document templates via the AddDocTemplate call,
after creating a new multi doc template. I use unique strings to
identify the file type and extension. However, the Open File dialog box
only displays files with the extension specified by the
first document template (first in the series of calls to
AddDocTemplate). This should be fairly simple to accomplish but I can't
get it to work. Any help, including examples,  would be appreciated.  

William J. Gibbons

Try overriding CWinApp::OnFileOpen()

Pierre V.