Gets or sets a UI that is automatically shown when an application starts.
Assembly: PresentationFramework (in PresentationFramework.dll)
You can use to automatically load a UI resource when an application starts.
The following table shows the types of UI resources that can be loaded, the type of window they are opened into, and the type of application that these resources can be set as the .
Typically, you set the property declaratively in XAML. However, you can set programmatically, such as from a Startup event handler, which is useful if for applications that can only load the necessary UI resources at run time. For example, an application might wait until run time to load its resources if the name of the UI resource is stored in a configuration file.
Whether you set declaratively or programmatically, the corresponding UI resource is not loaded until after the Startup event is handled. Consequently, you won't have access to the resulting window from either the Windows property or the MainWindow property when handling Startup.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.