How to set the Command property of the button part

Updated on Sep 15, 2025

Environment

Product Version	2019.2.618
Product	RadButtons for WPF

Description

How to bind the Command property of the RadButton element(the left part) inside the RadSplitButton.

Solution

Handle the Loaded event of the RadSplitButton, use the ChildrenOfType extension method in order to locate its RadButton child and set its Command property.

Example 1: Setting the Command of the RadButton inside the RadSplitButton

C#

	
    private void RadSplitButton_Loaded(object sender, RoutedEventArgs e)
    {
        var splitButton = (RadSplitButton)sender;
        var buttonPart = splitButton.ChildrenOfType<RadButton>().FirstOrDefault(x => x.Name == "ButtonPart");
        if (buttonPart != null)
        {
            buttonPart.Command = new DelegateCommand(OnExecute, OnCanExecute);
        }
    }

    private bool OnCanExecute(object obj)
    {
        // If this method returns false, only the button part of the RadSplitButton will be disabled
        return true;
    }

    private void OnExecute(object obj)
    {
        MessageBox.Show("Button clicked!");
    }

VB.NET

	
    Private Sub RadSplitButton_Loaded(ByVal sender As Object, ByVal e As RoutedEventArgs)
		Dim splitButton = DirectCast(sender, RadSplitButton)
		Dim buttonPart = splitButton.ChildrenOfType(Of RadButton)().FirstOrDefault(Function(x) x.Name = "ButtonPart")
		If buttonPart IsNot Nothing Then
			buttonPart.Command = New DelegateCommand(AddressOf OnExecute, AddressOf OnCanExecute)
		End If
	End Sub

	Private Function OnCanExecute(ByVal obj As Object) As Boolean
        ' If this method returns False, only the button part of the RadSplitButton will be disabled
		Return True
	End Function

	Private Sub OnExecute(ByVal obj As Object)
		MessageBox.Show("Button clicked!")
	End Sub

See Also

• DelegateCommand