CBasePropertyPage Class

A version of this page is also available for

Windows Embedded CE 6.0 R3

4/8/2010

This class is an abstract class for implementing a property page. Use this class if you are writing a filter (or other object) that supports property pages.

A property page is a COM object, so you must generate a GUID for the class identifier (CLSID) and provide an entry in the CFactoryTemplate Class array.

Your filter must expose the ISpecifyPropertyPages:IUnknown interface. This interface contains a single method, ISpecifyPropertyPages::GetPages, which returns the CLSID of the property page. The following example shows how to implement this method:

STDMETHODIMP CMyFilter::GetPages(CAUUID *pPages)
{
    if (!pPages) return E_POINTER;
    pPages->cElems = 1;
    pPages->pElems =reinterpret_cast<GUID*>(
                                    CoTaskMemAlloc(sizeof(GUID)));
    if (pPages->pElems == NULL) 
    {
        return E_OUTOFMEMORY;
    }
    *(pPages->pElems) = CLSID_MyPropPage;
    return S_OK;
} 

Remember to override the filter's NonDelegatingQueryInterface method as well. For more information, see INonDelegatingUnknown Interface**.

Next, create the dialog as a resource in your project, and create a string resource that holds the dialog title. Both of these resource IDs are parameters to the CBasePropertyPage constructor. Keeping the title string in a resource makes it easier to localize your property page.

The CBasePropertyPage class provides a framework for the IPropertyPage interface. This framework calls a number of virtual methods, including CBasePropertyPage::OnActivate, CBasePropertyPage::OnApplyChanges, and so on. In the base class, these methods simply return S_OK. Your derived class will need to override some or all of these virtual methods. For details, see the remarks for the individual methods.

Protected Member Variables

Public Methods

IPropertyPage Methods

Requirements

See Also

Reference

DirectShow Classes