Miscellaneous Constants

Miscellaneous String constants.

Constant/value	Description
wiaIDUnknown {00000000-0000-0000-0000-000000000000}	Unknown ID. Default value for the FormatID parameter for the [Transfer](-wiaaut-iitem-transfer.md), [ShowTransfer](-wiaaut-icommondialog-showtransfer.md), and [ShowAcquireImage](-wiaaut-icommondialog-showacquireimage.md) methods. In this context, it implies any FormatID rather than an unknown FormatID, or you might think of it as unknown to the calling application. Any property that represents a GUID can also return this constant as an error result. The following example shows how to determine if the file returned from [ShowAcquireImage](-wiaaut-icommondialog-showacquireimage.md) is in a known format. Dim Img 'As ImageFile Set Img = CommonDialog1.ShowAcquireImage If Img.FormatID = wiaIDUnknown Then MsgBox "Image format unknown" End If
wiaAnyDeviceID *	DeviceID for any Device. Default value for the DeviceID parameter for the [RegisterEvent](-wiaaut-idevicemanager-registerevent.md), [UnregisterEvent](-wiaaut-idevicemanager-unregisterevent.md), [RegisterPersistentEvent](-wiaaut-idevicemanager-registerpersistentevent.md), and [UnregisterPersistentEvent](-wiaaut-idevicemanager-unregisterpersistentevent.md) methods. This constant is defined here in case you want to explicitly use any device when calling these methods. For example code, see [Download New Items as They are Created](-wiaaut-shared-samples.md) in Shared Samples.

Requirements

Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2003 R2 [desktop apps only]
Header	Wiaaut.h
IDL	Wiaaut.idl