FIX: ClassWizard Generates Incorrect UDN_DELTAPOS Handler

The information in this article applies to:

- The ClassWizard included with:

   Microsoft Visual C++, 32-bit Edition, version 2.1, 2.2

SYMPTOMS

ClassWizard creates incorrect code for a handler for the UDN_DELTAPOS notification message of the CSpinButtonCtrl common control.

RESOLUTION

The generated handler function will look like this (assuming that the CSpinButtonCtrl is in a dialog):

  void CAboutDlg::OnDeltaposSpin1(NMHDR* pNMHDR, LRESULT* pResult)
      {
      NM_UPDOWN;
      // TODO: Add your control notification handler code here

      *pResult = 0;
      }

  void CAboutDlg::OnDeltaposSpin1(NMHDR* pNMHDR, LRESULT* pResult)
      {
      NM_UPDOWN* pUpDown = (NM_UPDOWN*)pNMHDR;

      // TODO: Add your control notification handler code here

      *pResult = 0;
      }

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This problem was corrected in Visual C++, 32-bit Edition, version 4.0.

REFERENCES

For more information about the CSpinButtonCtrl and the up down common control, please see the Class Library Reference in Books Online and the Win32 Software Development Kit (SDK) documentation.