IMFAttributes::GetUnknown method (mfobjects.h)
Retrieves an interface pointer associated with a key.
HRESULT GetUnknown(
[in] REFGUID guidKey,
[in] REFIID riid,
[out] LPVOID *ppv
);
[in] guidKey
GUID that identifies which value to retrieve. The attribute type must be MF_ATTRIBUTE_IUNKNOWN.
[in] riid
Interface identifier (IID) of the interface to retrieve.
[out] ppv
Receives a pointer to the requested interface. The caller must release the interface.
The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.
Return code | Description |
---|---|
|
The method succeeded. |
|
The attribute value is an IUnknown pointer but does not support requested interface. |
|
The specified key was not found. |
|
The attribute value is not an IUnknown pointer. |
This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed:
- Windows XP with Service Pack 2 (SP2) and later.
- Windows XP Media Center Edition 2005 with KB900325 (Windows XP Media Center Edition 2005) and KB925766 (October 2006 Update Rollup for Windows XP Media Center Edition) installed.
Requirement | Value |
---|---|
Minimum supported client | Windows Vista [desktop apps | UWP apps] |
Minimum supported server | Windows Server 2008 [desktop apps | UWP apps] |
Target Platform | Windows |
Header | mfobjects.h (include Mfidl.h) |
Library | Mfuuid.lib |