using System;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;
public class MainClass : Window
{
[STAThread]
public static void Main()
{
Application app = new Application();
app.Run(new MainClass());
}
public MainClass()
{
Content = "";
}
protected override void OnTextInput(TextCompositionEventArgs args)
{
base.OnTextInput(args);
string str = Content as string;
if (args.Text == "\b")
{
if (str.Length > 0)
str = str.Substring(0, str.Length - 1);
}
else
{
str += args.Text;
}
Content = str;
}
}