How can I use attributes for a property defined in the other half of a partial class?

Question

I have an autogenerated class from importing a web service containing something like this (abbreviated):

[System.Runtime.Serialization.DataMemberAttribute()]
public System.DateTime StartDate 
{
    get 
    {
        return this.StartDateField;
    }
    set { /* implementation prop changed */ }
}

And I want to add an MVC format attribute to this member. Therefore, in another file containing the same definition partial class, I would like to do something like the following (which is illegal):

[DisplayFormat(DataFormatString = "{0:dd-MM-yyyy}", ApplyFormatInEditMode = true)] 
public DateTime StartDate;

The partial method is useless here because partial methods must be private, have a return type, must be a method, etc. etc.

How can I decorate this item?

Answer 1

You can use the attribute MetadataTypeas follows:

[MetadataType(typeof(MyClass_Validation))]     
public partial class MyClass
{} 

public class MyClass_Validation     
{     
   [DisplayFormat(...)] 
   public DateTime StartDate { get; set; } 
}