I see a strange behaviour dragging in Line shape over a Canvas that I cannot explain. The Line shape is in a Thumb DataTemplate like so:
<DataTemplateDataType="{x:Type vm:MyLine}"><ThumbDragDelta="Thumb_DragDelta"><Thumb.Template><ControlTemplateTargetType="Thumb"><LineFill="LightBlue"StrokeThickness="2"Y1="{Binding Y1}"Y2="{Binding Y2}"X1="{Binding X1}"X2="{Binding X2}"Stroke="LightBlue"x:Name="Line"/></ControlTemplate></Thumb.Template></Thumb></DataTemplate>
The Canvas is ItemsPanelTemplate of
a ListBox.
In the ListBox.ItemContainerStyle there
is noCanvas.Top or Canvas.Left Binding
or Setter. Also no Binding for Width and Height.
The Line on the Canvs is dragging but it drifts away from the mouse position. Fairly wild and quick.
In code behind the dragging has the effect:
line.X1 += e.HorizontalChange; line.X2 += e.HorizontalChange;
line.Y1 += e.VerticalChange; line.Y2 += e.VerticalChange;
The setters for X..Y raise PropertyChanged otherwise
the Line wouldn't
move.
What should I do for a proper dragging behaviour for Line and
why? Binding
Mode=OneWay makes no difference.