validate phone number

Today in C#, I will teach you how to create a program that will validate an inputted phone number using C#. So, 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 2010: Go to File, click New Project, and choose Windows Application. 2. Next, add one TextBox named TextBox1 which will be used to input the phone number.