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Object Properties

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Object Properties

Windows Portable Devices supports the following object properties.

Property VarType Description
WPD_OBJECT_BACK_REFERENCES VT_LPWSTR The object ID of the container object. For example, an audio object within a mediacast would use this property to refer back to the parent Mediacast object.
WPD_OBJECT_CAN_DELETE VT_BOOL A Boolean value that specifies whether the given object can be deleted.
WPD_OBJECT_CONTAINER_FUNCTIONAL_OBJECT_ID VT_LPWSTR The object ID of the closest functional object that contains this object. For example, a file inside a storage functional object will have this property set to the ID of the storage functional object.
WPD_OBJECT_CONTENT_TYPE VT_CLSID A GUID identifying the generic type of this object (for example, a document or e-mail). This can be an object type defined by Windows Portable Devices, or a custom driver content type. The device object is the only object that does not report this property.
WPD_OBJECT_DATE_AUTHORED VT_DATE A value that specifies the date and time that the content was created. This may not be the same as the creation date of the file. For example, a music file has an authoring date of when the music was recorded, but a creation date of when the WMA file was actually created on the device.
WPD_OBJECT_DATE_CREATED VT_DATE A value that specifies the date and time the object was created on the device.
WPD_OBJECT_DATE_MODIFIED VT_DATE A value that specifies the date and time the object was modified on the device.
WPD_OBJECT_FORMAT VT_CLSID A GUID identifying the format of the object data. This can be a format defined by Windows Portable Devices or a custom driver format.
WPD_OBJECT_GENERATE_THUMBNAIL_FROM_RESOURCE VT_BOOL A Boolean value that specifies whether the thumbnail image for this object should be created from the default resource data.

This provides a way for objects without a thumbnail resource to provide a friendlier browsing experience. Using this flag may affect the first display response, since the application must retrieve and calculate a thumbnail image from the device; it is more efficient to provide a separate thumbnail image resource, if possible.

WPD_OBJECT_ID VT_LPWSTR A string ID that uniquely identifies the object on the device. This ID need not be stored across sessions.

If this property is both unique and persistent, the driver may set both WPD_OBJECT_PERSISTENT_UNIQUE_ID and WPD_OBJECT_ID to the same value.

WPD_OBJECT_IS_DRM_PROTECTED VT_BOOL A Boolean value that specifies whether the media data is DRM-protected. If not present, this is assumed to be False.
WPD_OBJECT_ISHIDDEN VT_BOOL A Boolean value that specifies whether the object should be hidden. If not present, the object is assumed to not be hidden.
WPD_OBJECT_CAN_DELETE VT_BOOL A Boolean value that specifies whether the object can be deleted, or not.
WPD_OBJECT_ISSYSTEM VT_BOOL A Boolean value that specifies whether the object represents system data (such as a system file). If not present, the object is assumed to not be a system object.
WPD_OBJECT_KEYWORDS VT_LPWSTR String containing a list of space-delimited keywords associated with this object.
WPD_OBJECT_NAME VT_LPWSTR The display name for the object.
WPD_OBJECT_NON_CONSUMABLE VT_BOOL A Boolean value that specifies whether this object is intended to be understood or merely stored by the device. If this property is not present, all data is assumed to be intended for consumption.
WPD_OBJECT_ORIGINAL_FILE_NAME VT_LPWSTR A string name for the file.
WPD_OBJECT_PARENT_ID VT_LPWSTR The object ID of the parent object. The only object that can return an empty string for this value is the root device object.

To modify this property, call IPortableDevice::SendCommand (WPD_COMMAND_STORAGE_MOVE).

WPD_OBJECT_PERSISTENT_UNIQUE_ID VT_LPWSTR A string ID that uniquely identifies the object on the device, similar to WPD_OBJECT_ID, but it must be stored across sessions.

If the object identifier (WPD_OBJECT_ID) is both unique and persistent, the driver may set both WPD_OBJECT_PERSISTENT_UNIQUE_ID and WPD_OBJECT_ID to the same value.

WPD_OBJECT_REFERENCES VT_UNKNOWN An IPortableDevicePropVariantCollection containing a collection of VT_LPWSTR object IDs identifying the referenced objects. This is only required if the object is a reference object such as a folder or playlist.
WPD_OBJECT_SIZE VT_UI8 The size of the object resource data.
WPD_OBJECT_SYNC_ID VT_LPWSTR An opaque string created by a client to retain state between sessions without retaining a catalogue of connected device content.

Requirements

Header: Defined in PortableDevice.h

See Also

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