WPF C#

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Only Numbers" Height="300" Width="300">
    
        
        
        
    
    

//File:Window.xaml.cs
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
namespace RoutedEvents
{
    public partial class OnlyNumbers : System.Windows.Window
    {
        public OnlyNumbers()
        {
            InitializeComponent();
        }
        private void pnl_PreviewTextInput(object sender, TextCompositionEventArgs e)
        {
            short val;
            if (!Int16.TryParse(e.Text, out val))
            {
                e.Handled = true;
            }            
        }
        private void pnl_PreviewKeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Space)
            {
                e.Handled = true;
            }
        }
    }
}