IMFAttributes::GetUnknown Method
Retrieves an interface pointer associated with a key.
Syntax
HRESULT GetUnknown(
[in] REFGUID guidKey,
[in] REFIID riid,
[out] LPVOID *ppv
);
Parameter
guidKey [in]
GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_IUNKNOWN.riid [in]
Interface identifier (IID) of the interface to retrieve.ppv [out]
Receives a pointer to the requested interface. The caller must release the interface.
Rückgabewert
The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.
| Rückgabecode | Beschreibung |
|---|---|
| S_OK | The method succeeded. |
| E_NOINTERFACE | The attribute value is an IUnknown pointer but does not support requested interface. |
| MF_E_ATTRIBUTENOTFOUND | The specified key was not found. |
| MF_E_INVALIDTYPE | The attribute value is not an IUnknown pointer. |
Hinweise
This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed:
- Windows XP mit Service Pack 2 (SP2) und höher.
- Windows XP Media Center Edition 2005 with KB900325 (Windows XP Media Center Edition 2005) and KB925766 (Oktober 2006 Updaterollup für Windows XP Media Center Edition) installed.
Anforderungen
Mindestens unterstützter Client |
Windows Vista |
Mindestens unterstützter Server |
Windows Server 2008 |
Header |
Mfobjects.h (include Mfidl.h) |
Bibliothek |
Mfuuid.lib |