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Application.RootVisual Property

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Gets or sets the main application UI.

Namespace:  System.Windows
Assembly:  System.Windows (in System.Windows.dll)


Public Property RootVisual As UIElement
public UIElement RootVisual { get; set; }

Property Value

Type: System.Windows.UIElement
A UIElement that is the main application UI.


Exception Condition

When setting this property, the specified value is not an instance of a class that derives from UIElement.


You can set the value of the RootVisual property only one time from code, although you get its value any number of times.


The following code example demonstrates how an application can use a Startup event handler to set the RootVisual property.

Partial Public Class App
    Inherits Application

    public Sub New()
    End Sub

    Private Sub Application_Startup(ByVal o As Object, _
        ByVal e As StartupEventArgs) Handles Me.Startup

        Me.RootVisual = New Page()

    End Sub

End Class
using System.Windows; // Application, StartupEventArgs

namespace SilverlightApplication
    public partial class App : Application
        public App()

        private void Application_Startup(object sender, StartupEventArgs e)
            // Specify the main application UI
            this.RootVisual = new Page();

Version Information


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.