Silverlight ChildWindow is centered over the parent control. I have extended ChildWindow to open it at a specific position.

Here is a live demo : childwindow-positioning-demo
And here is the code :
public partial class ChildWindowEx : ChildWindow { Point _pt = new Point(0,0); public ChildWindowEx() { InitializeComponent(); } public ChildWindowEx(Point pt) : this() { _pt = pt; } protected override Size ArrangeOverride(Size finalSize) { Grid grid = Utils.FindChild(this, "ContentRoot"); if (grid != null) { grid.Arrange(new Rect(_pt.X, _pt.Y, grid.DesiredSize.Width, grid.DesiredSize.Height)); return finalSize; } return base.ArrangeOverride(finalSize); } }
Visual Studio 2010 Solution : download