WPF transparent borders causes the UI to stop redrawing

Question

As a follow up to my previous question, I am wondering how to use transparent windows correctly. If I have set my window to use transparency, the UI will occasionally appear to stop responding. What is actually happening is that the UI simply is not updating as it should. Animations do not occur, pages do not appear to navigate; however, if you watch the debugger clicking on buttons, links, etc.. do actually work. Minimizing and restoring the window "catches up" the UI again and the user can continue working until the behavior comes back. If I remove the transparent borders, the behavior does not occur. Am I doing something wrong or is there some other setting, code, etc... that I need to implement to work with transparent borders properly? Here is my window declaration for the code that fails. And the code that does not exhibit the behavior JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

Are you using .NET 3.0, or .NET 3.5 on Windows XP SP2? If so, this is a known problem with the transparent window API that has been fixed in .NET 3.5 and SP3 of XP (and I think SP1 of Vista). Basically when you set the AllowsTransparency to True, the WPF pipeline has to render in software only mode. This will cause a significant degradation in performance on most systems. Unfortunately, the only thing you can do to fix this is to upgrade to .NET 3.0 SP1 (included in .NET 3.5), and install the appropriate service pack for Windows. Note that the transparent windows are still slower, but not nearly as bad. You can find a more in-depth discussion here.