How to use ODBC in an ActiveX control by using Visual C++

DBCTL demonstrates a way to use ODBC in an ActiveX Control (OLE Control). A Visual C++ and a Visual Basic client application are included as part of this sample. The Visual C++ client is called DBUSR, the Visual Basic client is called DBVBUSR.

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Notes

• Use the -d option when running DBCTL.EXE to decompress the file and recreate the proper directory structure.
• To make the DBCTL sample compile in Microsoft Visual C++ 6.0, you will have to either remove the "_UNICODE" preprocessor directive in the project settings or include the "afxdb.h" header file in DBCtlSet.h.

DBCTL creates and opens a Class Wizard-configured CRecordset object from within the virtual override of COleControl::OnSetClientSite. The CRecordset- derived object is configured to the COURSE table of the STDREG32.MDB that comes with the sample. Please note that you have to create a user or a system DSN called "student registration" in your ODBC control panel with Access ODBC Driver and have to point this DSN to the STDREG32.MDB file.

The CRecordset-derived object is closed from within its own destructor. The CRecordset object is destructed with a call to the delete operator from within the COleControl derived class destructor.

The control exposes one method, a DisplayRecords method, that simply lists the contents of the recordset in the control.

The OLE Control subclasses a listbox. The string items are added to the listbox by using SendMessage.

The DBUSR.EXE and DBVBUSR.EXE demonstrate using the custom control.