Validating numeric input
Fortunately you don’t have to create these patterns, you can find any pattern here, Implement user validation using regex and C# In this example I’ll show you how to use regex class to validate an email, zip code and phone number field within a windows form app.
In addition to providing instructions, validate user input to help users avoid mistakes.
Client side validation is performed by a web browser, before input is sent to a web server.In this article I’ll try to explain what regular expression is and how you can use its class in your C# app to validate a user input. A regular expression is a specific pattern used to parse and find matches in strings. A regular expression is sometimes called regex or regexp. \.[a-z A-Z]$ “ matches an email address, so you can use this pattern to validate if a specific string is equals to a valid email address or not. Regual Expressions namespace So let’s start, Now you can fill the fields then click check button, if there is any invalid data a message box will appear and tell you. is used for input fields that should contain an e-mail address.Depending on browser support, the e-mail address can be automatically validated when submitted.