ASP.Net MVC 3 DataAnnotations validating List<T>

I have a View开发者_运维知识库Model that has been deserialized from JSON which looks something like this:

public class UserThingsUpdateViewModel
{
    public IList<Thing> Things { get; set; }
    [Required]
    public int UserId { get; set; }
    public int Age { get; set; }
}

Thing is also a ViewModel which also has various DataAnnotaion ValidationAttribute attributes on the properties.

The problem is that Lists don't seem to get validated and even after a through search I cant seem to find any articles that tackle this. Most suggest that the ViewModel is wrong if it includes a list.

So, what is the best way to validate my list and add Model Errors to the Model State?

Prior to checking ModelState.IsValid, you could add code to step through and validate each Thing, as follows:

foreach (var thing in Things)
    TryValidateModel(thing);

This will validate each item, and add any errors to ModelState.

You could write a custom validator attribute and decorate the list property with it? That would allow you to write custom logic to get the elements out of the list and validate them.