Problem with DataAnnotations in partial class

问题

So in my mvc project's Project.Repository I have

[MetadataType(typeof(FalalaMetadata))]
public partial class Falala
{
    public string Name { get; set; }

    public string Age { get; set; }

    internal sealed class FalalaMetadata
    {
        [Required(ErrorMessage="Falala requires name.")]
        public string Name { get; set; }

        [Required(ErrorMessage = "Falala requires age.")]
        public string Age { get; set; }
    }
}

I use Falala as a model in my Project.Web.AccountControllers, and use a method to get violations. Validating worked when I had

public class Falala
{
    [Required]
    public string Name { get; set; }

    [Required(ErrorMessage="error")]
    public string Age { get; set; }
}

but not after using the partial class from above. I really need to use a partial class. What am I doing wrong here?

Thanks!

回答1:

I tend to use Metadata classes as followed.

[MetadataType(typeof(FalalaMetadata))]
public partial class Falala
{
    public string Name { get; set; }

    public string Age { get; set; }
}
public class FalalaMetadata
{
    [Required(ErrorMessage="Falala requires name.")]
    public string Name { get; set; }

    [Required(ErrorMessage = "Falala requires age.")]
    public string Age { get; set; }
}

Which works fine for me.

The following should also work (and is a better way to implement metadata classes):

[MetadataTypeAttribute(typeof(Falala.FalalaMetaData))]
public partial class Falala
{
    internal sealed class FalalaMetadata
    {
        [Required(ErrorMessage="Falala requires name.")]
        public string Name { get; set; }

        [Required(ErrorMessage = "Falala requires age.")]
        public string Age { get; set; }
    }
}

回答2:

I ran into a similar problem and finally got it working by putting both the Model class and the Metadata "buddy" class in the same namespace, even though my references seemed ok. I'm kind of a .net noob though so I'm not exactly comfortable with namespaces, could be something else.

回答3:

Could Internal on the nested class be the reason...?

I had a similiar problem and it seemed to all boiled down to not making the individual fields in the nested metadata class public - wonder if making the whole class internal causes the same problem?

回答4:

Not sure if this help, but I had a similar problem and spend days on it. At the end it was just a minor change which did the trick for me.

I changed UnobtrusiveJavaScriptEnabled to false in the config file

Good luck

来源：https://stackoverflow.com/questions/2105580/problem-with-dataannotations-in-partial-class

标签

asp.net-mvc

data-annotations

partial-classes