Marshal.PtrToStructure

[Michael Sync]

How can i use "Marshal.PtrToStructure" in VB6?

In my coding, I wrote like that

Public Property Get ObjectFromPtr(ByVal lPtr As Long) As EVENTMSG  ''Object
  Dim oTemp As EVENTMSG
  ' Turn the pointer into an illegal, uncounted interface
  CopyMemory oTemp, lPtr, 4
  ' Do NOT hit the End button here! You will crash!
  ' Assign to legal reference
  ObjectFromPtr = oTemp
  ' Still do NOT hit the End button here! You will still crash!
  ' Destroy the illegal reference
  CopyMemory oTemp, 0&, 4
  ' OK, hit the End button if you must
End Property


But It make crashing my program.
It would be great if you help me.

[Kelly Ethridge]

If EVENTMSG is the structure defined in the windows API then you're only copying the value in lPtr into the first 4 bytes of the EVENTMSG structure. There is no object in there.

So I have no idea what you are trying to accomplish with this code. What does lPtr point to?

[Michael Sync]

I got it.


Public Property Get ObjectFromPtr(ByVal lPtr As Long) As EVENTMSG ''Object
Dim oTemp As EVENTMSG
' Turn the pointer into an illegal, uncounted interface
CopyMemory oTemp, lPtr, Len(oTemp)
' Do NOT hit the End button here! You will crash!
' Assign to legal reference
ObjectFromPtr = oTemp
' Still do NOT hit the End button here! You will still crash!
' Destroy the illegal reference
CopyMemory oTemp, 0&, Len(oTemp)
' OK, hit the End button if you must
End Property


Actually, lPtr is one the parameters of JournalRecordProc. I 'm writing the program that can recorded a macro and can also play this macro by using JournalRecord Hook and JournalRecordPlayBack.

u know, JournalRecordProc function is still running even I have stopped my program. I already used UnhookWindowsHookEx API to uninstall JournalRecord Hook. But it's still running after Form_Unload().

[Michael Sync]

Oh. I have resolved this issue also.
I used wrong usage for UnhookWindowsHookEx.
Thanks.