How do I allow subclassing messages to occur during Do Loop without using DoEvents?

[tmighty2]

Hello!

I am using Ctrl + C to copy the currently selected text from an external application.

I am using subclassing to be notified when the clipboard contents has changed and the text is present in the clipboard.

Once WM_CHANGECBCHAIN is received, I check the clipboard's content.

My current approach looks like this:

Call SendCtrlC()

Dim lStart&
lStart = GetTickCount()

Do
    Dim lTaken&
    lTaken = GetTickCount() - lStart

    If lTaken > 3000 Then '3 seconds have passed. something must have gone wrong. Stop waiting for the clipboard change event
        Exit Do
    End If

    If (m_bCBChangeOccured) Then 'Does not work!
       'The problem is that m_bCBChangeOccured never becomes True in this loop! Because during the loop, we are not notified of the clipboard changes. Only if I use DoEvents, but I may not use DoEvents
       s = Clipboard.GetText()
       Exit Do
    End If
 
    'I can NOT use DoEvents() due to restrictions in coding standards which I have to follow
    'However, if I don't use DoEvents, I don't get the WM_CHANGECBCHAIN message
    'What could I do to let WM messages to occur within this loop?

Loop

And here in my form I have:

Private Sub iSubclass_WndProc(ByVal bBefore As Boolean, bHandled As Boolean, lReturn As Long, ByVal lng_hWnd As Long, ByVal uMsg As eMsg, ByVal wParam As Long, ByVal lParam As Long, lParamUser As Long)
   Select Case uMsg
   Case WM_CHANGECBCHAIN
      ' If the next viewer window is closing, repair the chain:
      m_hWndNextViewer = lParam
      If (m_hWndNextViewer <> 0) Then
         ' Otherwise if there is a next window, pass the message on:
         SendMessageByLong m_hWndNextViewer, uMsg, wParam, lParam
      End If
      lReturn = 0 'ISubclass_WindowProc = 0
        
   Case WM_DRAWCLIPBOARD
      ' the content of the clipboard has changed.
      ' We raise a ClipboardChanged message and pass the message on:
      m_bCBChangeOccured = True
      RaiseEvent ClipboardChanged

(...)
End Sub