Scan function (wiamicro.h)

The Scan function reads data from the device and returns the data to the WIA Flatbed driver.

Syntax

WIAMICRO_API HRESULT Scan(
  [in, out] PSCANINFO pScanInfo,
            LONG      lPhase,
  [out]     PBYTE     pBuffer,
            LONG      lLength,
  [out]     LONG      *plReceived
);

Parameters

[in, out] pScanInfo

Specifies the SCANINFO structure that represents the microdriver's settings. This is stored by the WIA Flatbed driver to guarantee that the settings between the microdriver and the WIA Flatbed driver are synchronized.

lPhase

Specifies the scan phase requested. This parameter can be set to one of the following values.

Value	Meaning
SCAN_FIRST	This signals the first phase of the scan. The microdriver performs three tasks: it initializes the device, it uses the data in the SCANINFO structure to set up the scan (for example, set the resolution, the start position, the width and the height on the device), and it starts the scan. Data must be returned from this call. Data must be put into the buffer pointed to by pBuffer and the pReceived parameter must be set to the amount of data put in the buffer.
SCAN_NEXT	This will be repeatedly called during the data transfer. Data should be put into the buffer pointed to by pBuffer and the pReceived parameter must be set to the amount of data put in the buffer.
SCAN_FINISHED	This will be called at the end of the scan to terminate the scanning process. No data should be transferred. SCAN_FINISHED will always be called even if the user cancels the scan. The microdriver should stop transferring data and the scanner should be reset so that it is ready for the next scan. The data returned from this function should be in raw format without any header. The data can be either packed or planar, aligned or unaligned, and in RGB or BGR order. Set the RawDataFormat, RawPixelOrder, and bNeedDataAlignment members of the SCANINFO structure appropriately in response to the CMD_INITIALIZE command.

[out] pBuffer

Specifies the buffer that will be filled with scanned data by the microdriver. This buffer is allocated by the WIA Flatbed Driver and is guaranteed to be at least lLength bytes in length.

lLength

Specifies the requested amount of data that will be scanned. The microdriver must never overfill the buffer pointed to by pBuffer.

[out] plReceived

Specifies the amount of data actually scanned into pBuffer. This value should never exceed the value of lLength, but can be less.

Return value

If the function succeeds, it returns S_OK. If the function fails, it returns a standard COM error code.

Requirements

Requirement	Value
Target Platform	Desktop
Header	wiamicro.h (include Wiamicro.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe

See also

SCANINFO

WIA Microdriver Commands

WIA Microdriver Structures