Code Coverage for .dll Source file

[C# Programming]

I have code coverage tool for NUnit i.e NCover. In my test solution I added my source code as .NET dll .When I run my test solution to using NCover it gives code coverage of test solution instead of my Sorcu Code dll. How NCover can give code coverage of dll? or it is mendatory to add source code as aproject in test solution??

Ethan Hunt 008
"Licensed to Code"
10th Cloud Corp
Banglaore
India