How to Use RadWindow as MainWindow

Updated on Oct 8, 2025

Environment

Product Version	2019.1.220
Product	RadWindow for WPF and Silverlight

Description

How to Use RadWindow as MainWindow.

Solution

1. First open the MainWindow.xaml file and replace the Window declaration with a RadWindow declaration:

XAML

	  <telerik:RadWindow x:Class="RadWindowAsMainWindow.MainWindow"
		  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
		  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
		  xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
		  Header="MainWindow" Height="350" Width="525">
	  ...
	  </telerik:RadWindow>

and in code-behind:

C#

	public partial class MainWindow : RadWindow
	{
	}

2. Remove StartupUri from the Application definition inside App.xaml:

XAML

  <Application x:Class="RadWindowAsMainWindow.App"
	  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  ...

3. Then override the OnStartup method of the Application class to show the RadWindow:

C#

  public partial class App : Application
  {
	  protected override void OnStartup(StartupEventArgs e)
	  {
	  new MainWindow().Show();
	  base.OnStartup(e);
	  }
  }

See Also

• RadWindowInteropHelper
• Host WebBrowser in RadWindow
• Use RadWindow as User Control