DOCUMENT:Q192883 07-MAY-2001 [visualc]
TITLE :HOWTO: Modify the VC++ COMPLEXDB Sample to Work on a Web Page
PRODUCT :Microsoft C Compiler
PROD/VER:winnt:6.0
OPER/SYS:
KEYWORDS:kbtemplate kbDatabase kbInternet kbVC600 kbATL300 kbGrpDSVCDB
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The information in this article applies to:
- Microsoft Visual C++, 32-bit Enterprise Edition, version 6.0
- Microsoft Visual C++, 32-bit Professional Edition, version 6.0
- Microsoft Visual C++, 32-bit Learning Edition, version 6.0
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SUMMARY
=======
Visual C++, version 6.0 contains a sample called COMPLEXDB that demonstrates how
to use the Active Template Library (ATL) to write a complex data bound control.
While the control works when placed into an MFC dialog as the sample
demonstrates, additional work needs to be done to use the control from a Web
page. This article details those steps.
MORE INFORMATION
================
Perform the following steps to get the COMPLEXDB sample to work on a Web page.
1. Create a CDataSourceListener class that is derived from DataSourceListener
(DataSourceListener is described in the ActiveX Control Writer's Kit).
2. Add the following code to the end of the ComplexCtl.cpp:
class CDataSourceListener : public DataSourceListener
{
public:
ULONG m_ulRefCount;
CComplexCtl * m_pControl;
CDataSourceListener(CComplexCtl * pControl):m_ulRefCount(0),
m_pControl(pControl){}
STDMETHOD(QueryInterface)(REFIID iid, LPVOID * ppvObject)
{
if (IsEqualIID(__uuidof(IUnknown), iid) ||
IsEqualIID(__uuidof(DataSourceListener), iid))
{
*ppvObject = this;
AddRef();
return S_OK;
}
else
return E_NOINTERFACE;
}
STDMETHOD_(ULONG, AddRef)()
{
return m_ulRefCount++;
}
STDMETHOD_(ULONG, Release)()
{
if (--m_ulRefCount == 0)
{
delete this;
return 0;
}
else
return m_ulRefCount;
}
STDMETHOD(dataMemberChanged)(DataMember bstrDM)
{
m_pControl->UpdateControl();
return S_OK;
};
STDMETHOD(dataMemberAdded)(DataMember bstrDM){return S_OK;};
STDMETHOD(dataMemberRemoved)(DataMember bstrDM){return S_OK;};
};
3. Modify the CComplexCtl::putref_DataSource() method in CComplexCtl.cpp file to
the following:
STDMETHODIMP CComplexCtl::putref_DataSource(DataSource* pDataSource)
{
m_spDataSource = pDataSource;
CDataSourceListener * pListener = new CDataSourceListener(this);
// Listener object is deleted when it is released.
m_spDataSource->addDataSourceListener(pListener);
}
4. Create the Web page to bind the data source object to the COMPLEXDB control.
The following example uses the RDS.DataControl control to bind data to the
COMPLEXDB control:
Sample Query Page
Sample Query Page
NOTE: The Internet Client SDK documentation shows that you can use the
following syntax: