Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
287 views
in Technique[技术] by (71.8m points)

c# - Creating custom data annotation validation in MVC 3

For instance, I have an Employee view model. When creating an employee, I want to validate the username to make sure it doesn't exist.

public class EmployeeViewModel
{
    [ScaffoldColumn(false)]
    public int EmployeeId { get; set; }

    [ValidateDuplicate(ErrorMessage = "That username already exists")]
    [Required(ErrorMessage = "Username is required")]
    [DisplayName("Username")]
    public string Username { get; set; }
}

And then have my ValidateDuplicate function somewhere with the code to check for a duplicate.

Is this possible?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

I would suggest looking at remote validation. The example even matches your case.

Basically, add the remote attribute to your viewmodel property that points to a controller action

[Remote("IsUserExists", "Account", ErrorMessage = "Can't add what already exists!")]
[Required(ErrorMessage = "Username is required")]
[DisplayName("Username")]
public string Username { get; set; }

which does your work

public ActionResult IsUserExists(string userName) 
{
 if (!UserService.UserNameExists(userName) || (CurrentUser.UserName == userName))
 {
      return "Ok.";
 }
}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...