举个例子吧:
32位系统的申明: Public Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
64位系统的申明: Public Declare PtrSafe Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As LongPtr, ByVal nIndex As LongPtr) As LongPtr
比较一下二者之间的差别吧