隐藏Vista / Windows 7 WPF FileDialog.Filter中的扩展名

I am using the WPF OpenFileDialog and SaveFileDialog in my .NET 4 WPF application. I use the Filter property to allow the user to set different file filters. In .NET 4, this uses the native file dialogs introduced with Windows Vista (if possible).I am using the WPF OpenFileDialog and SaveFileD