IMFAttributes Interface
Provides a generic way to store key/value pairs on an object. The keys are GUIDs, and the values can be any of the following data types: UINT32, UINT64, double, GUID, wide-character string, byte array, or IUnknown pointer. The standard implementation of this interface holds a thread lock while values are added, deleted, or retrieved.
For a list of predefined attribute GUIDs, see Media Foundation Attributes. Each attribute GUID has an expected data type. The various "set" methods in IMFAttributes do not validate the type against the attribute GUID. It is the application's responsibility to set the correct type for the attribute.
To create an empty attribute store, call MFCreateAttributes.
Mitglieder
IMFAttributesSchnittstelle erbt von der IUnknown-Schnittstelle. IMFAttributes umfasst auch die folgenden Typen von Mitgliedern:
- Methoden
Methoden
IMFAttributesSchnittstelle umfasst die folgenden Methoden.
| Methode | Beschreibung |
|---|---|
| Compare | Compares the attributes on this object with the attributes on another object. |
| CompareItem | Queries whether a stored attribute value equals a specified PROPVARIANT. |
| CopyAllItems | Copies all of the attributes from this object into another attribute store. |
| DeleteAllItems | Removes all key/value pairs from the object's attribute list. |
| DeleteItem | Removes a key/value pair from the object's attribute list. |
| GetAllocatedBlob | Retrieves a byte array associated with a key. This method allocates the memory for the array. |
| GetAllocatedString | Retrieves a wide-character string associated with a key. This method allocates the memory for the string. |
| GetBlob | Retrieves a byte array associated with a key. |
| GetBlobSize | Retrieves the length of a byte array associated with a key. |
| GetCount | Retrieves the number of attributes that are set on this object. |
| GetDouble | Retrieves a double value associated with a key. |
| GetGUID | Retrieves a GUID value associated with a key. |
| GetItem | Retrieves the value associated with a key. |
| GetItemByIndex | Retrieves an attribute at the specified index. |
| GetItemType | Retrieves the data type of the value associated with a key. |
| GetString | Retrieves a wide-character string associated with a key. |
| GetStringLength | Retrieves the length of a string value associated with a key. |
| GetUINT32 | Retrieves a UINT32 value associated with a key. |
| GetUINT64 | Retrieves a UINT64 value associated with a key. |
| GetUnknown | Retrieves an interface pointer associated with a key. |
| LockStore | Locks the attribute store so that no other thread can access it. |
| SetBlob | Associates a byte array with a key. |
| SetDouble | Associates a double value with a key. |
| SetGUID | Associates a GUID value with a key. |
| SetItem | Associates an attribute value with a key. |
| SetString | Associates a wide-character string with a key. |
| SetUINT32 | Associates a UINT32 value with a key. |
| SetUINT64 | Associates a UINT64 value with a key. |
| SetUnknown | Associates an IUnknown pointer with a key. |
| UnlockStore | Unlocks the attribute store. |
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 |