This example requires that a Text Box and Error Provider control have been created on a form. Index Of("@")) Then error Message = "" Return True End If End If error Message = "Email address must be valid email address format." Control Chars. Validating Dim error Msg As String If Not Valid Email Address(text Box1. Doing so can cause your application or the operating system to stop responding.
If second cell is filled and other first, third, fourth and fifth is not filled then validator should pop.
When users enter data into your application, you may want to verify that the data is valid before your application uses it.
If you do not set the Cancel property, Windows Forms will assume that validation succeeded for that control, and raise the Validated event.
For a code example that validates an email address in a Text Box, see Validating.
If you need to require users to enter data in a well-defined format, such as a telephone number or a part number, you can accomplish this quickly and with minimal code by using the Masked Text Box control.
A is a string made up of characters from a masking language that specifies which characters can be entered at any given position in the text box. If the user types an incorrect entry, for example, the user types a letter when a digit is required, the control will automatically reject the input.
For example, if you have a text box that must contain a postal code, you can perform the validation in the following ways: The Validating event is supplied an object of type Cancel Event Args.
If you determine that the control's data is not valid, you can cancel the Validating event by setting this object's Cancel property to .
In this case, to perform validation in the Validated event, change the control's Data Source Update Mode property (under (Databindings)\(Advanced)) from On Validation to Never, and add So when does a control's data get validated? You can use either implicit or explicit validation, depending on the needs of your application.