Step 2. Implement ISpecifyPropertyPages
Microsoft DirectShow 9.0 |
Step 2. Implement ISpecifyPropertyPages
Next, implement the ISpecifyPropertyPages interface in your filter. This interface has a single method, GetPages, which returns an array of CLSIDs for the property pages that the filter supports. In this example, the filter has a single property page. Start by generating the CLSID and declaring it in your header file:
// Always create new GUIDs! Never copy a GUID from an example. DEFINE_GUID(CLSID_SaturationProp, 0xa9bd4eb, 0xded5, 0x4df0, 0xba, 0xf6, 0x2c, 0xea, 0x23, 0xf5, 0x72, 0x61);
Now implement the GetPages method**:**
class CGrayFilter : public ISaturation, public ISpecifyPropertyPages, /* Other inherited classes. */ { public: STDMETHODIMP GetPages(CAUUID *pPages) { if (pPages == NULL) return E_POINTER; pPages->cElems = 1; pPages->pElems = (GUID*)CoTaskMemAlloc(sizeof(GUID)); if (pPages->pElems == NULL) { return E_OUTOFMEMORY; } pPages->pElems[0] = CLSID_SaturationProp; return S_OK; } }; /* ... */ }
Allocate memory for the array using CoTaskMemAlloc. The caller will release the memory.
Next: Step 3. Support QueryInterface.
See Also