The DDX_CBIndex function manages the transfer of int data between a combo box control in a dialog box, form view, or control view object and a int data member of the dialog box, form view, or control view object.
A pointer to a CDataExchange object. The framework supplies this object to establish the context of the data exchange, including its direction.
The resource ID of the combo box control associated with the control property.
A reference to a member variable of the dialog box, form view, or control view object with which data is exchanged.
When DDX_CBIndex is called, index is set to the index of the current combo box selection. If no item is selected, index is set to 0.
For more information about DDX, see Dialog Data Exchange and Validation.