To validate email input control I use EmailAdressAttribute . Can I somehow specify that only gmail.com valid domain?

  • But this example will not work? msdn.microsoft.com/en-us/library/ms753962(v=vs.100).aspx - VladD
  • @VladD; I do not quite understand how to create such an attribute using this example. - Lightness
  • Instead of creating an attribute, you can simply validate it as in the example. - VladD
  • @VladD; You can simply, but I wanted to understand how to create such an attribute. - Lightness

1 answer 1

You can peep the EmailAddressAttribute implementation on the Reference Source and create your own attribute for validation by slightly correcting the regular expression:

 [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter, AllowMultiple = false)] public sealed class GmailAddressAttribute : DataTypeAttribute { private static Regex _regex = new Regex(@"^((([az]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([az]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@gmail\.com$", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture); public GmailAddressAttribute() : base(DataType.EmailAddress) { ErrorMessage = "The {0} field is not a valid e-mail address."; } public override bool IsValid(object value) { if (value == null) { return true; } string valueAsString = value as string; return valueAsString != null && _regex.Match(valueAsString).Length > 0; } }