private delegate int LowLevelKeyboardProc(int nCode,WindowsMessages wParam, [In] KBDLLHOOKSTRUCT lParam);
VB.NET Definition:
Private Delegate Function LowLevelKeyboardProc(ByVal nCode As Integer, ByVal wParam As WindowsMessages, <[In]> ByVal lParam As KBDLLHOOKSTRUCT) As Integer