如何在WPF中覆盖线的StrokeThickness属性

Question

Here is the problem that has been with me for the past several days. I have 10000+ Line objects on a Canvas and a Slider that I use to scale the canvas to create a zoom effect. Everything is OK and the performance is great.

The only thing that bothers me is that the StrokeThickness of the Line gets scaled too. I tried to Bind the StrokeThickness to the inverse of the slider's value so that I get a uniform thickness whenever I move the slider. This worked but has decreased the performance substantially.

Is there any other way that would be suitable to this situation. I want to have a zero-width line thickness no matter how far I scale the canvas (like in CAD programs).

Answer 1

For the effect you want to achieve, overriding the StrokeThickness doesn't really mean anything as the it's value actually remains the same even if the ScaleTransform is changed.

The approach that you tried - Bind the StrokeThickness to the inverse of the slider's value - seems to be the most plausible one. To improve performance, instead of setting the StrokeThickness directly to inverse of Slider's value, set it to another property on your view model.

Then, in the event where sliding is completed, set the value of that property to the inverse of StrokeThickness .

Example -

private void OnSlidingComplete(object sender, EventArgs e)
{
    LineStrokeThickness = GetInverseOfZoomValue();
}

I know that this is not exactly a solution, rather a workaround.