Validating text box in vb
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post has been edited by modi123_1: 07 April 2010 - AM 0 Then i = 0 Message Box.
This is why I decided to make use of Regular Expressions here within this article.Today you will learn how to use regular Expressions to validate user input.In simple terms, validation refers to ensuring entered data is well, valid. They make use of a pattern matching system to match the input with a certain pattern of data.Also, the more tests you are performing, the slower your app might become. For more information regarding Regular Expressions, you are welcome to look at these two MSDN articles: Because it is always easy to learn by doing things practically, you will be creating an app that makes use of Regular Expressions to determine valid input. NET application and design the form to resemble Figure 1. Obviously this only works for the formatting of the email.Figure 1 - These objects will determine if all our data is valid or not. Clear() 'Clear Text Box Name Valid = False 'Boolean = False Else Name Valid = True 'Everything Fine End If End Sub Easy one to start with. Focus() 'Set Focus To Text Box End If End Sub Private Sub txt Email_Lost Focus(sender As Object, e As System. Lost Focus Validate Email() 'Check Email Validity End Sub The expression may look horrible to the layman's eye, but look closer. To check if the user has entered an email that actually exists, you will have to find a different way such as to send a of some sorts.