Paste Event in a WPF TextBox

Question

I have created a custom control inheriting TextBox. This custom control is a numeric TextBox, only supporting numbers.

I am using OnP

Answer 1

The below code worked for me. I hope, it will help someone.

Use the below code if you are using Xceed RichTextBox control.

  

 private void CommandExecuted_PreviewExecuted(object sender, RoutedEventArgs e)
    {
        Xceed.Wpf.Toolkit.RichTextBox richTextBox =  (Xceed.Wpf.Toolkit.RichTextBox)sender;

        string rtbtext = StringFromRichTextBox(richTextBox);
        if ((e as ExecutedRoutedEventArgs).Command == ApplicationCommands.Paste)
        {
            // verify that the textbox handled the paste command
            if (Clipboard.GetText() > 2500)//Get copied text from clipboard
            {
                e.Handled = true;// prevent paste if length is more than 2500.
                return;
            }
        }
    } 

If you are using TextBlock, then use below code

TextBlock textBlock = (TextBlock)sender;

instead of this

Xceed.Wpf.Toolkit.RichTextBox richTextBox =  (Xceed.Wpf.Toolkit.RichTextBox)sender;

Rest all codes can remain the same as above for TextBlock as well.