only number

There are many fields in an information that we must only type a number in a textfield or in a textbox such as phone number, zip code, or any fields that must have a number type only. So, now we will begin this filtering a textbox into number only. Now, let's start this tutorial! 1. Let's start with creating a Windows Form Application for this tutorial by following the following steps in Microsoft Visual Studio: Go to File, click New Project, and choose Windows Application. 2.