IMFAttributes::GetItemByIndex Method
Retrieves an attribute at the specified index.
Syntax
HRESULT GetItemByIndex(
[in] UINT32 unIndex,
[out] GUID *pguidKey,
[in, out] PROPVARIANT *pValue
);
Parameter
unIndex [in]
Index of the attribute to retrieve. To get the number of attributes, call IMFAttributes::GetCount.pguidKey [out]
Receives the GUID that identifies this attribute.pValue [in, out]
Pointer to a PROPVARIANT that receives the value. This parameter can be NULL. If it is not NULL, the method fills the PROPVARIANT with a copy of the attribute value. Call PropVariantClear to free the memory allocated by this method.
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_INVALIDARG | Invalid index. |
Hinweise
To enumerate all of an object's attributes in a thread-safe way, do the following:
Call IMFAttributes::LockStore to prevent another thread from adding or deleting attributes.
Call IMFAttributes::GetCount to find the number of attributes.
Call GetItemByIndex to get each attribute by index.
Call IMFAttributes::UnlockStore to unlock the attribute store.
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 |