Namespace:System.Windows.Controls Assembly:PresentationFramework (in PresentationFramework.dll) XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
If a Page is hosted by a Frame, setting WindowWidth has no effect, but you can still get the value of WindowWidth.
A Page in an XAML browser application (XBAP) can only use WindowWidth to change the width of Windows Internet Explorer; the width cannot be changed by setting Width, MinWidth, or MaxWidth.
The minimum width of the Windows Internet Explorer window is 250 pixels. For browser-hosted pages, this means that the value of WindowWidth may not be applied if it would cause the total width of the Windows Internet Explorer window to be less than 250 pixels.