Validating event net
When this event is canceled in data-bound mode, the new value is not pushed to the underlying data source.
When this event is canceled in virtual mode, the Cell Value Pushed event will not be raised.
This will future proof your code as much as possible and prepare you for any breaking changes down the road to the internals of the Framework.
Run(form1) End Sub End Class Public Class Form1 Inherits System. Protected Overloads Overrides Sub Dispose(By Val disposing As Boolean) If disposing Then If Not (components Is Nothing) Then components. Dispose(disposing) End Sub Friend With Events Text Box1 As System.
Label 'Required by the Windows Form Designer Private components As System. Container 'NOTE: The following procedure is required by the Windows Form Designer 'It can be modified using the Windows Form Designer.
Resume Layout(False) End Sub #End Region Private Sub Text Box1_Text Changed(By Val sender As System.
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.
Determining whether or not data is valid can sometimes be a painstaking process as there are numerous tests that need to be thought of. This means that as a programmer, you have the power to supply the exact pattern for the input you desire in any text input field. Again, certain special characters are obviously not allowed.So, what I am trying to say is: make sure you understand other cultures, or be aware of people with uncommon names. Using Regular expressions here, is basically the standard, even though it is a bit messy. Focus() 'Return Focus End If End Sub Here, I created a separate function to do all the work.