how to use multiple AdditionalFields in remote validation - asp.net mvc

Question

I need to validate the duplicate of FirstName, LastName and Email Address combination using remote validation in my ASP.NET MVC 4 (C#) application. The Remote Validation accepts only one AdditionalFields, which is as below:

 [Remote("IsUserNameAvailable", "User", AdditionalFields="LastName" )]
 public string FirstName{ get; set; }
 public string LastName{ get; set; }
 public string EmailAddress{ get; set; }

How can i add the EmailAddress for the combination?

Answer 1

You could separate them by comma:

[Remote("IsUserNameAvailable", "User", AdditionalFields="LastName,EmailAddress" )]