Can I define properties in partial classes, then mark them with attributes in another partial class?

Question

Is there a way I can have a generated code file like so:

public partial class A  {     public string a { get; set; } } 

and then in another file:

public partial class A  {     [Attribute("etc")]     public string a { get; set; } } 

So that I can have a class generated from the database and then use a non-generated file to mark it up?

Answer 1

Here is the solution I have been using for such cases. It is useful when you have auto-generated classes that you want to decorate with attributes. Let's say this is the auto-generated class:

public partial class UserProfile {     public int UserId { get; set; }     public string UserName { get; set; }     public string Firstname { get; set; }     public string Lastname { get; set; } } 

And let's say, I would like to add an attribute to specify that UserId is the key. I would then create a partial class in another file like this:

[Table("UserProfile")] [MetadataType(typeof(UserProfileMetadata))] public partial class UserProfile {     internal sealed class UserProfileMetadata     {         [Key]         [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]         public int UserId { get; set; }     } }