Mvc远程属性在查询字符串中发送“未定义”

Question

I'm trying to remote validate some code and for the parameter, its passing undefined in as a parameters. Here is my validation code:

[OutputCache(Location = OutputCacheLocation.None, NoStore = true)]
public class ValidationController : Controller
{
    public JsonResult IsUserNameAvailable(string userName, int? UserId)
    {
        var users = new BusinessLayer.BdsAdmin.Users();
        if (UserId == null || UserId == 0)
            // Do something
        else // Do something else

        if (users.Count == 0)
        {
            return Json(true, JsonRequestBehavior.AllowGet);
        }

        string msg = string.Format("{0} is already taken and is not available.", userName);
        return Json(msg, JsonRequestBehavior.AllowGet);
    }
}

Here is my model:

public class EditUserAdministrationViewModel
{
    public int UserId { get; set; }

    [Required(ErrorMessage = "You must enter a user name.")]
    [Display(Name = "User Name")]
    [Remote("IsUserNameAvailable", "Validation", AdditionalFields = "UserId")]
    public string UserName { get; set; }

    // More properties
}

Looking at the request in Fiddler, here is what I see:

GET /Validation/IsUserNameAvailable?UserName=sara&UserId=undefined

Why is MVC injecting the string undefined into the request instead of the actual UserId?

Answer 1

You need to add

  @Html.HiddenFor(m=>m.UserId) 

at the view so that the binder will bind it to the remote validation controller or otherwise there is no value to bind