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Creating a CWnd Class for Printing, Not Viewing

Creating a CWnd Class for Printing, Not Viewing

Question:
After significant development time, a wonderful class derived from CWnd was created by our team to pull together text, graphics, etc. in a Paintbrush type of application. Now, we’d like to be able to print the created bitmap. This was fairly simple to implement. However, the wrinkle now is that we must be able to print these images without displaying them. The information regarding what to place, and where, is stored in a database. We don’t want to have to display the CWnd, but crank through several CRecordsets, and build the images, and print them.

What is the best way to accomplish this? Can you create a CWnd without displaying it? Can the DC be changed from painting to printing?

Answer:
It’s easy to create a CWnd without displaying it. Just keep it hidden. However, CWnd is probably not the class I would choose to derive from if I was not showing anything on screen.

Still, I might if I had to send messages to it or if I was trying to convert existing code as you are.

I can’t offer much help here except to say that you can change the DC from a window DC to a printer DC and most of the code that accesses the DC will continue to work. There are some differences with printing, however, such as keeping track of multiple pages and so on. For these differences, you will most likely need to make some changes to your code.

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