Dan Soltesz -blog .NET geek in disguise

I wanted to be able to allow my users the ability to right click in a textbox and have a contextmenu shown to be able to cut, copy and paste. I decided to create a behavior so that the functionality can easily be added to any textbox control.

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Interactivity;
 
namespace MyApp.Behaviors.TextBox
{
    public class TextBoxCutCopyPasteBehavior : Behavior<System.Windows.Controls.TextBox>
    {
        private ContextMenu _contextMenu;
        private MenuItem _copy;
        private MenuItem _cut;
        private MenuItem _paste;
        public TextBoxCutCopyPasteBehavior()
        {
 
            _contextMenu = new ContextMenu();
            _cut = new MenuItem();
            _cut.Header = "Cut";
            _cut.Click += new RoutedEventHandler(cut_Click);
            _contextMenu.Items.Add(_cut);
 
            _copy = new MenuItem();
            _copy.Header = "Copy";
            _copy.Click += new RoutedEventHandler(copy_Click);
            _contextMenu.Items.Add(_copy);
 
            _paste = new MenuItem();
            _paste.Header = "Paste";
            _paste.Click += new RoutedEventHandler(paste_Click);
            _contextMenu.Items.Add(_paste);
 
 
        }
 
        void paste_Click(object sender, RoutedEventArgs e)
        {
            AssociatedObject.SelectedText = Clipboard.GetText();
            _contextMenu.IsOpen = false;
        }
 
        void cut_Click(object sender, RoutedEventArgs e)
        {
            Clipboard.SetText(AssociatedObject.SelectedText);
            AssociatedObject.SelectedText = string.Empty;
            AssociatedObject.Focus();
            _contextMenu.IsOpen = false;
        }
 
        void copy_Click(object sender, RoutedEventArgs e)
        {
            Clipboard.SetText(AssociatedObject.SelectedText);
            AssociatedObject.Focus();
            _contextMenu.IsOpen = false;
        }
 
        protected override void OnAttached()
        {
 
            AssociatedObject.MouseRightButtonDown += new MouseButtonEventHandler(AssociatedObject_MouseRightButtonDown);
            AssociatedObject.MouseRightButtonUp += new MouseButtonEventHandler(AssociatedObject_MouseRightButtonUp);
            AssociatedObject.SetValue(ContextMenuService.ContextMenuProperty, _contextMenu);
            base.OnAttached();
        }
 
        void AssociatedObject_MouseRightButtonUp(object sender, MouseButtonEventArgs e)
        {
            if (Clipboard.ContainsText())
                _paste.IsEnabled = true;
            else
                _paste.IsEnabled = false;
 
            if (string.IsNullOrEmpty(AssociatedObject.SelectedText))
            {
                _cut.IsEnabled = false;
                _copy.IsEnabled = false;
            }
            else
            {
                _cut.IsEnabled = true;
                _copy.IsEnabled = true;
            }
            _contextMenu.IsOpen = true;
 
        }
 
        void AssociatedObject_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
        {
            e.Handled = true;
        }
 
        protected override void OnDetaching()
        {
            AssociatedObject.MouseRightButtonDown -= new MouseButtonEventHandler(AssociatedObject_MouseRightButtonDown);
            AssociatedObject.MouseRightButtonUp -= new MouseButtonEventHandler(AssociatedObject_MouseRightButtonUp);
            _contextMenu = null;
            base.OnDetaching();
 
        }
 
    }
}
 

Once the behavior is created we can now add to our TextBox

1. add a reference to System.Windows.Interactivity
2. In your xaml code add

   1. xmlns

      :i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"

   2. xmlns

      :behaviors="clr-namespace:MyApp.Behaviors.TextBox;assembly=MyApp"

   3.  <TextBox x:Name="myTextBox" >
             <i:Interaction.Behaviors>
                 <behaviros:TextBoxCutCopyPasteBehavior/>
             </i:Interaction.Behaviors>
         </TextBox>

That's it, now you have right click support for your textbox with cut, copy and paste.