In this example, we handle the click event of a button and display a message box. The event handler method receives an instance of RoutedEventArgs that represents the click event. Example 2:csharp private void TextBox_TextChanged(object sender, RoutedEventArgs e) { TextBox textBox = (TextBox)sender; string newText = textBox.Text; // Do something with the new text } ``` In this example, we handle the text changed event of a textbox. The event handler method receives an instance of RoutedEventArgs that represents the text changed event. We cast the sender parameter to a TextBox instance and use the Text property to get the new text. Package Library: System.Windows.RoutedEventArgs is part of the PresentationFramework.dll library in the .NET Framework.