private void RadRichTextBox_CommandExecuting(object sender, CommandExecutingEventArgs e) { if (e.Command is SaveCommand) { e.Cancel = true; SaveDocument(); // A custom logic for saving document so you can change the properties of the Save File dialog. } if (e.Command is PasteCommand) { // Altering the PasteCommand to ensure only plain text is pasted in RadRichTextBox. // Obtain the content from the clipboard. RadDocument documentFromClipboard = ClipboardEx.GetDocument().ToDocument(); TxtFormatProvider provider = new TxtFormatProvider(); // Convert it to plain text. string plainText = provider.Export(documentFromClipboard); // Create a RadDocument instance from the plain text. RadDocument documentToInsert = provider.Import(plainText); // Set this document as a content to the clipboard. ClipboardEx.SetDocument(new DocumentFragment(documentToInsert)); } if (e.Command is InsertTableCommand) { // Disable the possibility to insert tables into the document. MessageBox.Show("Inserting tables is not allowed."); e.Cancel = true; } }