#1,094 – Disabling Editing Operations in a TextBox

You can disable the cut/copy/paste features in a TextBox by handling the CommandManager.PreviewCanExecute event and checking for the associated editing commands.

A TextBox has implicit command bindings to support cut, copy, and paste commands.  When the user executes one of these commands, using the context menu or a keyboard shortcut, the associated routed command is executed, with the TextBox as the source.  You can short-circuit the command by intercepting PreviewCanExecute and making sure that CanExecute returns false.

Markup:

        <TextBox Name="txtSomeText"
                 CommandManager.PreviewCanExecute="txtSomeText_PreviewCanExecute"
                 Width="220" Height="25" Margin="10"/>

Code-behind:

        private void txtSomeText_PreviewCanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            if ((e.Command == ApplicationCommands.Cut) ||
                (e.Command == ApplicationCommands.Copy) ||
                (e.Command == ApplicationCommands.Paste))
            {
                e.Handled = true;
                e.CanExecute = false;
            }
        }

The editing functions are now disabled. The context menu in the TextBox shows the commands greyed out and corresponding keyboard shortcuts do nothing.

#933 – Cut/Copy/Paste Functionality in a TextBox

Cut, Copy and Paste functionality is automatically enabled for the text within a TextBox control.

You can select text in a TextBox by

• Left-clicking and dragging with the mouse
• Double-clicking to select a word
• Moving the arrow keys while holding down the Shift key
• Pressing Ctrl+A to select all text in the TextBox

With text selected, you can Cut or Copy selected text by

• Right-clicking and selecting Cut or Copy from the context menu
• Pressing Ctrl+X to Cut text (remove from TextBox and add to clipboard)
• Pressing Ctrl+C to Copy text (add to clipboard without removing)

You can Paste text from the clipboard into the TextBox at the current cursor location by

• Right-clicking and selecting Paste from the context menu
• Pressing Ctrl+V to Paste text

If you currently have text selected, doing a Paste operation will replace the selected text with text from the clipboard.