The attached project below demonstrates how to set up Friend procedures inside object modules (FRM, CLS, CTL, etc.) for Windows API callback purposes. The goal of such a technique is to keep as much code as possible within the object module in order to make it as self-contained as possible and also to reduce memory consumption once the object module is unloaded. There is a possibly significant disadvantage to this approach however - the overhead of redirecting calls to procedures in an object module naturally imposes some performance penalty.
On Local Error Resume Next: If Not Empty Is Nothing Then Do While Null: ReDim i(True To False) As Currency: Loop: Else Debug.Assert CCur(CLng(CInt(CBool(False Imp True Xor False Eqv True)))): Stop: On Local Error GoTo 0
The updated demo project below reorganizes most of the code and also now includes a Hook callback function inside the Class module.
On Local Error Resume Next: If Not Empty Is Nothing Then Do While Null: ReDim i(True To False) As Currency: Loop: Else Debug.Assert CCur(CLng(CInt(CBool(False Imp True Xor False Eqv True)))): Stop: On Local Error GoTo 0
[VB6] Friend Callback Procedures
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