How to represent a .net class library and its classes in the Visio? To me, the Package and the Class seems to represent the library and classes respectively. Any suggestions?
Modeling a library of classes in UML can be indeed done by modeling the library as a package and the classes in the library as UML classes belonging to the package. Then, classes will be identified by the combination PackageName::ClassName
To model this in Visio, once you have created the package, you can open model explorer, select the package and with the right button select new->class diagram.
Then a new class diagram will open. All classes created in that class diagram are automatically included as part of the package