Hi,

It is a dependency property and the Path object used in the ShapeNode template binds to it. It seems the Path itself does not handle the thickness change notification. However setting the stroke color works fine, so you might just assign the default color after thickness to force the Path to repaint:

node.StrokeThickness += 1;
node.Stroke = new SolidColorBrush(Colors.Black);

I hope that helps,
Stoyan

Yes, it does. What kind of Shape are you using?

Never mind, got it working.
The XAML template for my shape was not binding the StrokeThickness property of the Path.
I changed it into this:

<Path
				    Data="{TemplateBinding ShapeGeometry}"
				    Stroke="{TemplateBinding Stroke}"
				    StrokeThickness="{TemplateBinding StrokeThickness}"
				    Fill="{TemplateBinding Brush}" />
 

It was a copy-paste from your sample and i just overlooked this.
Thanks anyway for the solution!