c# - How can I prevent garbage collection from being called when calling ShowDialog on a xaml window?

Question

I have a application that's using a lot of memory, but for now I cannot change this fact. My problem is that I have an operation I'd like to perform and provide a progress dialog but it appears that displaying the xaml progress window is causing GC.Collect to be called 10 times! Any ideas how I can optimize opening my progress window?

According to my Ants Profiler the calls leading up to GC.Collect are

System.Window.ShowDialog() ->
..
..
System.Windows.Media.Imaging.BitmapSource.CreateCachedBitmap ->
SafeMILHandle.UpdateEstimatedSize ->
SafeMILHandleMemoryPressure.ctor ->
MemoryPressure.Add ->
MemoryPressure.ProcessAdd ->
GC.Collect

Answer 1

There is also a solution that would completely disable the bitmap image related memory pressure and subsequent garbage collection. It is more of a hack, but you can read about similar issue here.

typeof(BitmapImage).Assembly.GetType("MS.Internal.MemoryPressure").GetField("_totalMemory", BindingFlags.NonPublic | BindingFlags.Static).SetValue(null, Int64.MinValue / 2); 

This way you avoid searching all over your code to find and modify WPF icon initialization. On top of that some controls like System.Windows.Forms.Integration.ElementHost will implicitly add bitmap related memory pressure regardless of how you initialize.