Cannot have more than 4000 BitmapCacheBrush

Question

Hello,
Sorry for my bad english.
I cannot create more than 4000 BitmapCacheBrush. I think it's because there is a limit of 10000 GDI handle per process.
There is no error, but the application block.
The MSDN don't say anything about this limit (it should at least). Is there a workaround ?
Am I wrong if I say that BitmapCacheBrush use RenderTargetBitmap ? Which is bugged (see my last post at https://social.msdn.microsoft.com/Forums/vstudio/en-US/e6713faa-2d0d-4f28-b6b7-4e5213253538/releasing-rendertargetbitmap?forum=wpf).
Thank you for your help.

Answer 1

Thank you for your interest.
So, if BitmapCacheBrush do not use RenderTargetBitmap, I think both of them uses something that is bugged.
An exemple, here you are :
XAML :
<Window x:Class="WpfApplication.MainWindow"        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Button Grid.Row="0" Content="Click" Click="Click" />
<Viewport3D Grid.Row="1" x:Name="myViewport">
<Viewport3D.Camera>
<PerspectiveCamera LookDirection="-100 -100 -100" Position="100 100 100" UpDirection="0 0 1" />
</Viewport3D.Camera>
</Viewport3D>
</Grid>
</Window>
Code :
private void Click(object sender, RoutedEventArgs e)
ModelVisual3D model = new ModelVisual3D();
Model3DGroup group = new Model3DGroup();
PointCollection textTexturesCoordinate = new PointCollection(8) { new Point(0, 1), new Point(0, 0), new Point(1, 1), new Point(1, 0) };
Point3DCollection textPositions = new Point3DCollection(4) { new Point3D(0, 0, 0), new Point3D(1, 0, 0), new Point3D(1, 1, 0), new Point3D(0, 1, 0) };
Int32Collection textTriangleIndices = new Int32Collection(6) { 0, 3, 1, 0, 2, 3 };
MeshGeometry3D mesh = new MeshGeometry3D() { Positions = textPositions, TextureCoordinates = textTexturesCoordinate, TriangleIndices = textTriangleIndices };
for (int i = 0; i < 5000; i++)
group.Children.Add(new GeometryModel3D() { Material = GetDiffuseMaterial(i.ToString()), Geometry = mesh });
model.Content = group;
myViewport.Children.Add(model);
public DiffuseMaterial GetDiffuseMaterial(string text)
FormattedText formattedText = new FormattedText(text, CultureInfo.InvariantCulture, FlowDirection.LeftToRight, new Typeface("Verdana"), 12.0, Brushes.Black);
DrawingVisual drawingVisual = new DrawingVisual();
using (DrawingContext drawingContext = drawingVisual.RenderOpen())
drawingContext.DrawText(formattedText, new Point(0, 0));
return new DiffuseMaterial(new BitmapCacheBrush(drawingVisual));
When you push on the button "click", the application freeze.
If you change 5000 in 1000, then when you push on the button "click", the application doesn't freeze.
Edit : In my post, I said 4000, but it's approximative. The limit is between 4000 and 5000.