通过P/Invoke和Marshal问题访问Win32 API调用

I'm relatively new to .net/C# (though very experienced in Win32 / MFC and other platforms) and need to write a utility to talk to a custom USB HID device. The protocol is pretty simple and I already have a working utility written in MFC, but I would prefer to write the utility in .Net / C# as I'm trying to move with the times and leave MFC behind.I'm relatively new to .net/C# (though very expe