Dependency Property with type of DoubleCollection crash app in winui 3

Question

i have a custom control in my winui 3 app and i have a dp called LineStrokeDashArray dp defined like this:

testControl : Control
{
public DoubleCollection LineStrokeDashArray
{
    get { return (DoubleCollection)GetValue(LineStrokeDashArrayProperty); }
    set { SetValue(LineStrokeDashArrayProperty, value); }
}

public static readonly DependencyProperty LineStrokeDashArrayProperty =
    DependencyProperty.Register("LineStrokeDashArray", typeof(DoubleCollection), typeof(testControl), new PropertyMetadata(default(DoubleCollection)));

}

and in my style and ControlTemplate:

 <Line 
       VerticalAlignment="Center"
       Stretch="Fill"
       Stroke="{TemplateBinding LineStroke}"
       StrokeDashArray="{TemplateBinding LineStrokeDashArray}"
       StrokeEndLineCap="Square"
       StrokeStartLineCap="Square"
       StrokeThickness="{TemplateBinding LineStrokeThickness}"
       X2="1" />

now when i want to use my control like this:

<local:testControl LineStrokeDashArray="2,2" />

my app crash, i also tried new PropertyMetadata(new DoubleCollection())); and my app still crashing. i dont know why this is happening, and since this is a winui 3 app, there is no more info for crash and i get this :

enter image description here

---

Update: sample app:

App9.zip

Answer 1

It is determined by the personality of Shape.StrokeDashArray Property.

According to my test, you cannot bind a DoubleCollection to more than one shape!