Creating a touchscreen interface such as a numeric keypad

http://www.codeproject.com/Articles/267588/Creating-a-touchscreen-interface-such-as-a-numeric

Introduction

This article is intended to demonstrate how to create a touchscreen interface for WinForms, using a numeric keypad as an example.
This is not intended to be an in-depth discussion of UI principles, nor good programming practices. It is solely intended as a starting point for someone looking to develop a touchscreen application wondering how to get started.

Background

Why reinvent the wheel? For the last few years, I've needed to create various touchscreen interfaces for a warehouse environment. Recently, people (locally) have been asking how to begin writing for a touchscreen. This is intended to get someone started.
Why use a numeric keypad? Simply because this interface is used the most frequently across the environments we've designed for.