When you apply this attribute to a data field, you must follow the guidelines for the use of the validation attributes. For more information, see ASP.NET Dynamic Data Guidelines.

The following example shows how to use the RegularExpressionAttribute attribute to validate the FirstName and LastName data fields. The regular expression allows up to 40 uppercase and lowercase characters. The example performs the following tasks:

• Implements a metadata partial class and the associated metadata class.

• In the associated metadata class, applies the RegularExpressionAttribute attribute to the FirstName and LastName data fields, specifying the pattern and custom error messages.

Imports System
Imports System.Web.DynamicData
Imports System.ComponentModel.DataAnnotations


<MetadataType(GetType(CustomerMetaData))> _
Partial Public Class Customer


End Class

Public Class CustomerMetaData

    ' Allow up to 40 uppercase and lowercase 
    ' characters. Use custom error.
    <RegularExpression("^[a-zA-Z''-'\s]{1,40}$", _
                       ErrorMessage:="Characters are not allowed.")> _
    Public FirstName As Object

    ' Allow up to 40 uppercase and lowercase 
    ' characters. Use standard error.
    <RegularExpression("^[a-zA-Z''-'\s]{1,40}$")> _
    Public LastName As Object
End Class

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

.NET Framework

Reference