Primary Key for model in code first approach

Hai friends, I am doing code first approach:

Here is my model class:

public class RegUsers1

{

[KEY]  //but not coming. Its assigning 0 to Uid & throwing unable to save 

public int Uid { set; get; }

public string FullName { set; get; }

public string Email { set; get; }

public string Password { set; get; }

public string Gender { set; get; }

public string Qualification { set; get; }

}

 

For this class How to set primary key to Uid? I have used the [KEY] attribute. But I am unable to trace it is throwing an error by assigning 0 to uid while inserting. Is there any other option to [KEY]? Simply my question is how to set primary key to Uid in code first approach? Thank you