I\'ve download sample code with C#. but when I run I get this error message:
A project with an Output type of Class Library cannot be started direct
The currently selected startup project is a Class Library.
You need an entry point for your application. Does your solution contain multiple projects?
Are you sure you want to 'run' the Class Library?

Possibly you've downloaded a Class Library solution only. In that case there might be unit tests that you can 'debug' to step-trough the code.
Update In response to your comment, these are possibilities to run the class library: