編寫鉤子程式時，在程式碼：

hHook = SetWindowsHookEx(WH_MOUSE_LL, AddressOf HookProc, App.hInstance, 0)

處出現錯誤，提示'AddressOf' expression cannot be converted to 'Long' because 'Long' is not a delegate type.

SetWindowsHookEx的原來的定義如下：

 Private Declare Function SetWindowsHookEx Lib "user32" _ Alias "SetWindowsHookExA" (ByVal idHook As Long, ByVal _ lpfn As Long, ByVal hmod As Long, ByVal dwThreadId As _ Long) As Long

於是我新定義了一個和HookProc一樣的函式：

Public Delegate Function HookProcBase(ByVal nCode As Long, ByVal wParam As Long, ByVal lparam As Long) As Long

然後把SetWindowsHookEx改為：

Public Declare Function SetWindowsHookEx Lib "user32" _ Alias "SetWindowsHookExA" (ByVal idHook As Long, _ ByVal lpfn As HookProcBase, ByVal hmod As Long, ByVal _ dwThreadID As Long) As Long

這樣就沒有問題了。