If input is not a number do not handle the key event : Key Event « Windows Presentation Foundation « C# / CSharp Tutorial

<Window x:Class="RoutedEvents.OnlyNumbers"
    Title="Only Numbers" Height="300" Width="300">
    <StackPanel Margin="5" PreviewTextInput="pnl_PreviewTextInput" PreviewKeyDown="pnl_PreviewKeyDown">
        <TextBox Margin="3" AcceptsTab="False"></TextBox>
        <TextBox Margin="3"></TextBox>
        <TextBox Margin="3"></TextBox>

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()
        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;
WPF If Input Is Not A Number Do Not Handle The Key Event

24.122.Key Event
24.122.1.Query Left / Right control keyQuery Left / Right control key
24.122.2.Query Left / Right Shift keyQuery Left / Right Shift key
24.122.3.Is Key.CapsLock ToggledIs Key.CapsLock Toggled
24.122.5.Query Number lock keyQuery Number lock key
24.122.6.Use Keyboard.Focus to set the focus to a Text FieldUse Keyboard.Focus to set the focus to a Text Field
24.122.7.Programmatically Extract an Element's Style with DefaultStyleKeyPropertyProgrammatically Extract an Element's Style with DefaultStyleKeyProperty
24.122.8.Provide Quick Keyboard Access to ButtonsProvide Quick Keyboard Access to Buttons
24.122.9.Reading keyboard modifiersReading keyboard modifiers
24.122.10.Reading individual key state with Keyboard.IsKeyDownReading individual key state with Keyboard.IsKeyDown
24.122.11.Suppress Keyboard and Mouse EventsSuppress Keyboard and Mouse Events
24.122.12.Use KeyBinding to bind Key event to TextBox.InputBindingsUse KeyBinding to bind Key event to TextBox.InputBindings
24.122.13.StackPanel PreviewTextInput and PreviewKeyDownStackPanel PreviewTextInput and PreviewKeyDown
24.122.14.If input is not a number do not handle the key eventIf input is not a number do not handle the key event
24.122.15.On Key Down HandlerOn Key Down Handler
24.122.16.Check if it is a key down action
24.122.17.Check if it is a key up action
24.122.18.Record Key strokes
24.122.19.Override OnTextInput method to get the input from key board
24.122.20.TextBox key pressed action listener, and set caret index for TextBox
24.122.21.override key down method to listen to key down event
24.122.22.Check key code for Key.Up and Key.Down