FIX: CWnd::SubclassDlgItem Returns FALSE for OLE Controls

MORE INFORMATION

Steps to Help Reproduce Problem

1. Generate a default SDI control container application using AppWizard.
2. Insert the Grid OLE Control through the Component Gallery, which in turn generates the CGridCtrl wrapper class.
3. Place the Grid control in the Application's About dialog box.
4. Declare an embedded member variable called "m_gridctrl" in CAboutDlg of type CGridCtrl.
5. Generate an OnInitDialog() handler for the CAboutDlg class and subclass the Grid control inside it as illustrated by this code:

      BOOL CAboutDlg::OnInitDialog()
      {
          // Call base class implementation
          CDialog::OnInitDialog();
   
          // Try to subclass the Grid control by calling SubclassDlgItem
          m_gridctrl.SubclassDlgItem(IDC_GRID1, this);
   
          return TRUE;  // set focus to first control of the dialog
      }
   						

   NOTE: In this code, IDC_GRID1 is the ID of the Grid control.
6. When running the container application through the debugger, notice that CWnd::SubclassDlgItem returns FALSE after failing on the check for m_pCtrlCont != NULL in line 301 of Winctrl1.cpp.

Sample Code to Work Around Problem

BOOL CAboutDlg::OnInitDialog()
{
    CDialog::OnInitDialog();

    // Try to Subclass the Grid control by calling SubclassWindow
    CWnd* pWnd = GetDlgItem(IDC_GRID1);
    m_gridctrl.SubclassWindow(pWnd->m_hWnd);

    return TRUE;  // set focus to first control of the dialog
                  // Exception: OCX Property Pages should return FALSE
}