IWiaDataTransfer interface (wia_xp.h)

The IWiaDataTransfer interface is a high performance data transfer interface. This interface supports a shared memory window to transfer data from the device object to the application, and eliminates unnecessary data copies during marshalling. A callback mechanism is provided in the form of the IWiaDataCallback interface. It enables applications to obtain data transfer status notification, transfer data from the Windows Image Acquisition (WIA) device to the application, and cancel pending data transfers.

Note  For Windows Vista applications, use IWiaTransfer instead of IWiaDataTransfer.


The IWiaDataTransfer interface inherits from the IUnknown interface. IWiaDataTransfer also has these types of members:


The IWiaDataTransfer interface has these methods.


The IWiaDataTransfer::idtEnumWIA_FORMAT_INFO method creates a banded transfer implementation of the IEnumWIA_FORMAT_INFO interface.

The IWiaDataTransfer::idtGetBandedData method transfers a band of data from a hardware device to an application. For efficiency, applications retrieve data from Windows Image Acquisition (WIA) hardware devices in successive bands.

The IWiaDataTransfer::idtGetData method retrieves complete files from a Windows Image Acquisition (WIA) device.

The IWiaDataTransfer::idtGetExtendedTransferInfo retrieves extended information relating to data transfer buffers in the case of banded data transfers.

The IWiaDataTransfer::idtQueryGetData method is used by applications to query a Windows Image Acquisition (WIA) device to determine what types of data formats it supports.


The IWiaDataTransfer interface, like all Component Object Model (COM) interfaces, inherits the IUnknown interface methods.

IUnknown Methods Description
IUnknown::QueryInterface Returns pointers to supported interfaces.
IUnknown::AddRef Increments reference count.
IUnknown::Release Decrements reference count.


Minimum supported client Windows 2000 Professional, Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header wia_xp.h (include Wia.h)