why does my C# client that uses Library A need to have a using statement for Library B (which A uses)

Question

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 &a

Answer 1

If LibraryA exposes properties, returns objects from methods, or take parameters of types that are defined in LibraryB, and you declare or use a variable in Main Program of one of those types, you'll need the using statement.