Error: the entity type requires a primary key

Question

I would like to expand the question asked on this thread

Binding listbox to observablecollection

by giving it an ability to persistent the data. The structur

Answer 1

Make sure you have the following condition:

1. Use [key] if your primary key name is not Id or ID.
2. Use the public keyword.
3. Primary key should have getter and setter.

Example:

public class MyEntity {
   [key]
   public Guid Id {get; set;}
}