Rect Constructor (Double, Double, Double, Double)
Initializes a Rect structure that has the specified x-coordinate, y-coordinate, width, and height.
Assembly: System.Windows (in System.Windows.dll)
width and height can be negative if they are specified in XAML as part of the attribute string, with the result that the direction that the width or height applies to is inverted. For instance, a height of -20 will produce a Rect where the X,Y point is now the bottom left corner. However, the Rect constructor in the managed API does not permit negative values for width and height. You should adjust the coordinate reference of x,y, width and height such that the Rect can be specified using non-negative width and height values.