Weird performance problem with Shapes.Path

Hi,

I got a weird performance issue with the System.Windows.Shapes.Path class.

I have a loop creating about 40,000 paths into a Canvas. There are one or two handfuls of different Brushes used for the objects.

When I create a new SolidColorBrush for each iteration, the loop takes about 3.5 seconds:

Brush brStroke = null;
for (uint index = 0; index < count; index++)
   {
   System.Windows.Shapes.Path path = new System.Windows.Shapes.Path();

   path.Data = GetPathData();

   brStroke = new SolidColorBrush(GetColor(index));

   path.Stroke = brStroke;
   path.StrokeThickness = thickness;
   canvas.Children.Add(path);
   }

I thought I could speed this up a bit by creating a dictionary for the brushes and cache them. But this version of the loop takes 90 seconds!

Dictionary<ushort, Brush> brushes = new Dictionary<ushort,Brush>();
Brush brStroke = null;
for (uint index = 0; index < count; index++)
   {
   System.Windows.Shapes.Path path = new System.Windows.Shapes.Path();

   path.Data = GetPathData();

   ushort gt = GetColorTableIndex(index);
   if (brushes.ContainsKey(gt))
      brStroke = brushes[gt];
   else
      {
      brStroke = new SolidColorBrush(GetColor(index));
      brushes.Add(gt, brStroke);
      }

   path.Stroke = brStroke;
   path.StrokeThickness = thickness;
   canvas.Children.Add(path);
   }

Why that?

Does anybody have an idea?

Thanks,

Thomas