I can't Data Bind to a local variable in WPF/XAML

Question

I want a textbox to display the value of a variable when I click it (an iteration of 1 to 100), I do not know what I am doing Wrong:

When I run the project nothing i

Answer 1

Try this:

 public partial class MainWindow : Window, INotifyPropertyChanged
    {
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = this;
        }

        public string myText { get; set; }

        public void Button_Click_1(object sender, RoutedEventArgs e)
        {
            BackgroundWorker bw = new BackgroundWorker();
            bw.DoWork += delegate
            {
                int i = 0;
                for (i = 0; i < 100; i++)
                {
                    System.Windows.Threading.Dispatcher.CurrentDispatcher.Invoke((Action)(() => { myText = i.ToString(); OnPropertyChanged("myText"); }));                    
                    Thread.Sleep(100);
                }
            };

            bw.RunWorkerAsync();
        }

        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string name)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(name));
            }
        }
    }

XAML file: