[WPF] TextBox Delay TextChanged Event

    System.Windows.Forms.Timer _typingTimer; // WinForms
    // System.Windows.Threading.DispatcherTimer _typingTimer; // WPF

    public MainWindow()
    {
        InitializeComponent();
    }

    private void scanBox_TextChanged(object sender, EventArgs e)
    {
        if (_typingTimer == null)
        {
            /* WinForms: */
            _typingTimer = new Timer();
            _typingTimer.Interval = 300;
            /* WPF: 
            _typingTimer = new DispatcherTimer();
            _typingTimer.Interval = TimeSpan.FromMilliseconds(300);
            */

            _typingTimer.Tick += new EventHandler(this.handleTypingTimerTimeout);
        }
        _typingTimer.Stop(); // Resets the timer
        _typingTimer.Tag = (sender as TextBox).Text; // This should be done with EventArgs
        _typingTimer.Start(); 
    }

    private void handleTypingTimerTimeout(object sender, EventArgs e)
    {
        var timer = sender as Timer; // WinForms
        // var timer = sender as DispatcherTimer; // WPF
        if (timer == null)
        {
            return;
        }

        // Testing - updates window title
        var isbn = timer.Tag.ToString();
        windowFrame.Text = isbn; // WinForms
        // windowFrame.Title = isbn; // WPF

        // The timer must be stopped! We want to act only once per keystroke.
        timer.Stop();
    }