#include "ltwrappr.h"

virtual L_INT LWia::AcquireCallBack(pBitmap, pszFilename, uPercent, uFlags)


pointer to the bitmap handle

L_TCHAR * pszFilename;

file name

L_UINT32 uPercent;

the percent completion of the acquire process

L_UINT32 uFlags;

flags that indicates whether the device finished acquiring the page

This function will be called after calling any of the LWia::Acquire or LWia::AcquireSimple functions. And it will be enabled only if you enabled the callback functions by calling  LBase::EnableCallBack (TRUE).

Parameter Description
pBitmap Pointer to the bitmap handle that references the bitmap acquired from the WIA source.
pszFilename Character string containing the name of the file to which to save the scanned image(s). This parameter is valid only if the transfer mode is set to file transfer.
uPercent The percent completion of the page being scanned.
uFlags Flag that indicates the start or the end of the scanned page. Possible values are:
  Value Meaning
  0 Default value when this is not the first transferred chunk or the last transferred chunk.
  L_WIA_ACQUIRE_START_OF_PAGE [0x00000001] Indicates the start of the page being scanned.
  L_WIA_ACQUIRE_END_OF_PAGE [0x00000002] Indicates the end of the page being scanned. Use this value to reset the progress bar.



The function was successful.


The callback wants to abort the scanning operation.

< 1

An error occurred. Refer to Return Codes.


This feature is available in LEADTOOLS version 16 or higher.

This callback will be called through the acquire process to provide the user with the percent completed of the process so he can update his progress bar and at the end it provides him/her with the bitmap handle after its prepared (if the user is doing memory transfer) and also passes the user the L_WIA_ACQUIRE_END_OF_PAGE flag in the uFlags parameter to indicate each end of page.

To prevent memory leaks, the user should free the bitmap within the callback function.


If you are using WIA 2.0 while the L_WIA_SHOW_USER_INTERFACE is set then no need to provide a callback pointer since Microsofts WIA 2.0 acquire dialog doesnt provide a callback and it does all the process and return back to you with the saved files count and paths.

Required DLLs and Libraries


For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

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