IWiaImageFilter::InitializeFilter method

Initializes the filter. Called by Windows Image Acquisition (WIA) 2.0 before each image download.

Syntax

HRESULT InitializeFilter(
  [in] IWiaItem2            *pWiaItem2,
  [in] IWiaTransferCallback *pWiaTransferCallback
);

Parameters

pWiaItem2 [in]

Type: IWiaItem2*

Specifies a pointer to the IWiaItem2 item that represents the preview image.

pWiaTransferCallback [in]

Type: IWiaTransferCallback*

Specifies a pointer to the application's IWiaTransferCallback interface.

Return value

Type: HRESULT

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

Remarks

This method is called when an application calls Download and when an application calls the WIA 2.0 Preview Component's GetNewPreview function. IWiaImageFilter::InitializeFilter stores the references to pWiaItem2 and pWiaTransferCallback to pass into these functions. These two interface pointers should be stored as member variables and IUnknown::AddRef should be called for each. The interface pointers are also needed in the filter's implementation of TransferCallback and GetNextStream during image acquisition.

Requirements