Up one directory from the leap.dll and leapcsharp.dll is LeapCSharp.NET3.5.dll
and LeapCSharp.NET4.0.dll
.
(LeapDeveloperKit\LeapSDK\lib)
These are the tools for Visual studio references.
If you want to use the leap.dll file then you'll need to use P/Invoke
EDIT:
Perhaps you could check out this leap tutorial, complete with code examples.
Here is a better P/Invoke tutorial.
Using an application like DLL Export Viewer you can see all the methods available for your leap dll's. These would be your entry points using P/Invoke. There is also a PInvoke assistance tool that will write your c# for you.
However, doing this with the leap.dll
:
[DllImport("leap.dll")]
public static extern bool hasFocus();
Is the same as doing this with the LeapCSharp.Net4.0
dll reference:
Leap.Controller con = new Controller();
var focus = con.HasFocus;
So you dont need both sets of DLL's.