Hi,

I have:

• Main Program Class - uses Library A
• Library A - has partial classes which mix in methods from Library B
• Library B - mix in methods & interfaces

Why would I need a using statement to LibaryB just to get their extension methods working in the main class? That is given that it's Library B that defines the classes that will be extended.

EDIT - Except from code

    // *** PROGRAM ***
    using TopologyDAL;
    using Topology;  // *** THIS WAS NEEDED TO GET EXTN METHODS APPEARING ***
    class Program
    {
        static void Main(string[] args)
        {
            var context = new Model1Container();
            Node myNode;  // ** trying to get myNode mixin methods to appear seems to need using line to point to Library B ***
         }
     }


// ** LIBRARY A
namespace TopologyDAL
{
    public partial class Node
    {
        // Auto generated from EF
    }

    public partial class Node : INode<int>   // to add extension methods from Library B
    {
        public int Key
    }
}

// ** LIBRARY B
namespace ToplogyLibrary
{
    public static class NodeExtns
    {
        public static void FromNodeMixin<T>(this INode<T> node) {
           // XXXX
        }
    }
    public interface INode<T> 
    {
        // Properties
        T Key { get; }

        // Methods
    }

}