FIX: Error C2065: 'DDX_FieldCBIndex' : undeclared identifier

ID: Q132396

The information in this article applies to:

The ClassWizard, included with:
- Microsoft Visual C++ for Windows
- Microsoft Visual C++ 32-bit Edition, versions 2.0, 2.1, 2.2

SYMPTOMS

When you use ClassWizard to map a drop list combobox to a foreign CRecordset object's field through a record view integer member variable, ClassWizard generates a call to DDX_FieldCBIndex in the record view's DoDataExchange() member function:


   void CMyRecordView::DoDataExchange(CDataExchange* pDX)
   {
      ...
      //{{AFX_DATA_MAP(CMyRecordView)
      DDX_FieldCBIndex(pDX, IDC_COMBO1, m_pSet->m_id, m_pSet);
      //}}AFX_DATA_MAP
   }

When compiling the program, the compiler gives you the following compiler error:

error C2065: 'DDX_FieldCBIndex' : undeclared identifier

CAUSE

The DDX_FieldCBIndex function is not implemented by the Microsoft Foundation Classes.

RESOLUTION

Do not bind the integer data member of the record view to a drop down combo box. Bind the data member to an edit control.

STATUS

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

MORE INFORMATION

When implementing CRecordView and CRecordSet classes, ClassWizard completes two data exchanges. Data is exchanged between the record view control and the record view data members and between it and the record set data members, which are linked to the database fields.


                  RFX                          DDX

    Data          Record                       Dynamic
    Source  <---- Field   --->   record   <--- Data --->   controls
    record        Exchange       view          Exchange
    set

For record view data members that have a corresponding database field, the DDX_Fieldxxx set of functions are used to perform DDX. For those members without corresponding database fields, the DDX_xxx set of functions are used. For every DDX_xxx function, there is typically a corresponding DDX_Fieldxxx function.

The corresponding data exchange function for DDX_FieldCBIndex() is DDX_CBIndex(), which obtains the index position of the item in the listbox portion of the combobox. This information is meaningless outside of the combo box unless it corresponds to a predefined string. If this is the case, then the data member should be bound to an edit control.

REFERENCES

For more information on binding record view fields to recordset objects, please see the following MFC Encyclopedia articles:

ClassWizard: Mapping Form Controls to Recordset Fields
ClassWizard: Foreign Objects

Additional query words: 1.50 1.51 1.52 2.00 2.10 2.20

Keywords : kbwizard kbMFC kbVC
Version : winnt:
Platform : winnt
Issue type :