jeff123wang

Declare PtrSafe Function DispCallFunc Lib "OleAut32.dll" (ByVal pvInstance As Long, ByVal offsetinVft As Long, ByVal CallConv As Long, ByVal retTYP As Integer, ByVal paCNT As Long, ByRef paTypes As Integer, ByRef paValues As Long, ByRef retVAR As Variant) As Long
Declare PtrSafe Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
Declare PtrSafe Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, ByVal lpProcName As String) As Long

Const CC_STDCALL = 4

Public Function stdCallA(sDll As String, sFunc As String, ByVal RetType As VbVarType, ParamArray P() As Variant)

    Dim i As Long, pFunc As Long, V(), HRes As Long
    ReDim V(0)

jeff123wang

VB6 and VBA come with no support for function pointers.

Also, when you wish to execute a function in a dll using the Declare function, you can only call functions created by the Steadcall calling conversation.

These constraints can be avoided by using the DispCallFunc API. The DispCallFunc is widely used in VB6 when erasing the history of IE. Although the DispCallFunc is known as API for calling the IUnknown interface, in fact, you can also perform other functions other than COM by passing the NULL to the first argument.

As explained in the http://msdn.microsoft.com/en-us/library/ms221473(v=vs.85).aspx , the DispCallFunc argument is as follows.

jeff123wang

Option Explicit

Private Declare Function GetPrivateProfileString Lib "kernel32" Alias "GetPrivateProfileStringA" (ByVal lpSectionName As String, ByVal lpKeyName As Any, ByVal lpDefault As String, ByVal lpbuffurnedString As String, ByVal nBuffSize As Long, ByVal lpFileName As String) As Long
Private Declare Function WritePrivateProfileString Lib "kernel32" Alias "WritePrivateProfileStringA" (ByVal lpSectionName As String, ByVal lpKeyName As Any, ByVal lpString As Any, ByVal lpFileName As String) As Long
Private Declare Function FreeLibrary Lib "kernel32" (ByVal hLibModule As Long) As Long
Private Declare Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
Private Declare Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, ByVal lpProcName As String) As Long
Private Declare Function GetModuleHandle Lib "kernel32.dll" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As Long
Private Declare Function DispCallFunc Lib "oleaut32.dll" (ByVal pvInstance A

jeff123wang

' Need to add project references to C:\Windows\Microsoft.NET\Framework\v2.0.50727\mscoree.tlb and mscorlib.tlb

Private Declare PtrSafe Function DispCallFunc Lib "oleaut32.dll" (ByVal pv As LongPtr, ByVal ov As LongPtr, ByVal cc As Integer, ByVal vr As Integer, ByVal ca As Long, ByRef pr As Integer, ByRef pg As LongPtr, ByRef par As Variant) As Long
Private Declare PtrSafe Sub RtlMoveMemory Lib "kernel32" (Dst As Any, Src As Any, ByVal BLen As LongPtr)
Private Declare PtrSafe Function VarPtrArray Lib "VBE7" Alias "VarPtr" (ByRef Var() As Any) As LongPtr

#If Win64 Then
Const LS As LongPtr = 8&
#Else
Const LS As LongPtr = 4&

jeff123wang

Option Explicit

Private Declare PtrSafe Function FindWindow Lib "user32.dll" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As LongPtr
Private Declare PtrSafe Function SetWindowLong Lib "user32.dll" Alias "SetWindowLongA" (ByVal hWnd As LongPtr, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare PtrSafe Function CallWindowProc Lib "user32.dll" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hWnd As LongPtr, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As LongPtr) As LongPtr
Private Declare PtrSafe Function SendMessage Lib "user32.dll" Alias "SendMessageA" (ByVal hWnd As LongPtr, ByVal Msg As Long, ByVal wParam As LongPtr, ByVal lParam As LongPtr) As LongPtr
Private Declare PtrSafe Function SetClipboardViewer Lib "user32.dll" (ByVal hWndNewViewer As LongPtr) As LongPtr
Private Declare PtrSafe Function ChangeClipboardChain Lib "user32.dll" (ByVal hWndRemove As LongPtr, ByVal hWndNewNext As LongPtr) As Long
Private Declare Function IsClip