ArtOfWords.App.OnStartup C# (CSharp) Method

        protected override void OnStartup(StartupEventArgs e)
        {
            // Select the text in a TextBox when it receives focus.
            EventManager.RegisterClassHandler(typeof(TextBox), TextBox.PreviewMouseLeftButtonDownEvent,
                new MouseButtonEventHandler(SelectivelyIgnoreMouseButton));
            EventManager.RegisterClassHandler(typeof(TextBox), TextBox.GotKeyboardFocusEvent,
                new RoutedEventHandler(SelectAllText));
            EventManager.RegisterClassHandler(typeof(TextBox), TextBox.MouseDoubleClickEvent,
                new RoutedEventHandler(SelectAllText));
            base.OnStartup(e);
        }