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IWiaTransferCallback::TransferCallback method

Provides progress and other notifications during a transfer.

Syntax


HRESULT TransferCallback(
  [in]  LONG lFlags,
  [in]  WiaTransferParams *pWiaTransferParams
);

Parameters

lFlags [in]

Type: LONG

Currently unused. Should be set to zero.

pWiaTransferParams [in]

Type: WiaTransferParams*

Specifies a pointer to a WiaTransferParams structure.

Return value

Type: HRESULT

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

When this method is implemented by an image processing filter, the Windows Image Acquisition (WIA) 2.0 minidriver calls it during image acquisition to send progress messages back to the application.

A filter's IWiaTransferCallback::TransferCallback must delegate to the application callback's IWiaTransferCallback::TransferCallback method. Usually, the filter stream filters the data passed to it and writes the filtered data directly to the application provided stream. When image processing filter stores data between calls to its IStream::Write method, it must also modify the lPercentComplete and ulBytesWrittenToCurrentStream values in the WiaTransferParams structure.

Requirements

Minimum supported client

Windows Vista [desktop apps only]

Minimum supported server

Windows Server 2008 [desktop apps only]

Header

Wia.h

IDL

Wia.idl

Library

Wiaguid.lib

 

 

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