When creating a new GUI, is WPF the preferred choice over Windows Forms?
If you only care about supporting Windows and don't mind the time it takes to learn it, go with WPF. It's fast, flexible, easy to reskin, and has great tools to work with it.
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Is there any way to automate windows forms testing?
AutomatedQA's TestComplete is a good testing application to automate GUI testing. It supports more than just Windows Forms also, so you can reuse it for other applications. It is not open source and this is the best that I have found. I haven't seen an open source equivalent to WatiN. It does have a free trial, for you decide if you like it or not. The main reason I went with it, is that it really is cost effective, compared to other testing applications.
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Is there a standard way to return values from custom dialogs in Windows Forms?
I've always done it exactly the way you're describing. I'm curious to see if there's a more accepted approach.
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Is it appropriate to use "Wingdings" fonts in a Windows Forms or WPF app?
I think that nice solution would be taking the glyphs you like from Wingdings, and converting them to WPF shapes, as resources of your app. This will add just a few kB to your app and you won't be dependent on Wingdings.
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How to smoothly animate Windows Forms location with different speeds?
If you got the results you want with a FPS value of 300 then I would go with that. The concept of Frames Per Second for WinForms is not the same as graphic-intensive video games, so a high value won't be a problem. The FPS value here simply adjusts how often the code is executed.
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