Deleting a Content Control in a Context Menu

Updated on Apr 1, 2026

Environment

Product	RichTextBox for UI for WPF
Version	2026.1.211

Description

I need to delete a content control from the RichTextBox when using a custom context menu in the ContextMenu_Showing event.

This knowledge base article also answers the following questions:

• How to add a "Remove Content Control" option inside a RichTextBox context menu?
• How to delete a content control from a document in RichTextBox for WPF?
• How to handle content control deletion through a custom menu in RichTextBox?

Solution

To delete a content control, use the SelectAnnotationRange method of the Selection property of the RadDocument class. Pass the SdtRangeStart instance of the clicked content control as a parameter. Then, invoke the Delete method of the ActiveDocumentEditor property of the RadRichTextBox control.

Follow these steps:

1. Handle the ContextMenu_Showing event to add a menu option for removing the content control.
2. Implement logic to detect if the caret is over a content control.
3. Use the SelectAnnotationRange method to select the content control and the Delete method to remove it.

Here is an example implementation:

csharp

private void ContextMenu_Showing(object sender, Telerik.Windows.Controls.RichTextBoxUI.Menus.ContextMenuEventArgs e)
{
    if (IsCaretOverContentControl())
    {
        RadMenuItem menuItem = new RadMenuItem()
        {
            Header = "Remove Content Control"
        };
        menuItem.Click += MenuItem_Click;

        ContextMenuGroup contextMenuGroup = new ContextMenuGroup();
        contextMenuGroup.Add(menuItem);
        e.ContextMenuGroupCollection.Add(contextMenuGroup);
    }
}

private void MenuItem_Click(object sender, Telerik.Windows.RadRoutedEventArgs e)
{
    SdtRangeStart sdtRangeStart = GetContainingSdtRangeStart(this.rtb.Document.CaretPosition);
    if (sdtRangeStart == null || sdtRangeStart.SdtEnd == null)
        return;

    this.rtb.Document.Selection.SelectAnnotationRange(sdtRangeStart);
    this.rtb.ActiveDocumentEditor.Delete(false);
}

private bool IsCaretOverContentControl()
{
    var caretPosition = this.rtb.Document.CaretPosition;

    SdtRangeStart sdtStart = GetContainingSdtRangeStart(caretPosition);
    return sdtStart != null;
}

private SdtRangeStart GetContainingSdtRangeStart(DocumentPosition caretPosition)
{
    var paragraph = caretPosition.GetCurrentParagraph();
    if (paragraph == null)
        return null;

    var element = caretPosition.GetCurrentInline();
    DocumentElement current = element as DocumentElement;

    while (current != null)
    {
        if (current is SdtRangeEnd)
            return null;

        if (current is SdtRangeStart sdtStart)
            return sdtStart;

        current = current.PreviousSibling;
    }

    return null;
}

Key Details:

• The ContextMenu_Showing event customizes the context menu by adding a "Remove Content Control" option.
• The MenuItem_Click method performs the deletion by selecting and removing the content control.

See Also

• RichTextBox Overview
• Context Menu Customization in RichTextBox
• RadRichTextBox API Reference