LWia::AcquireToFile

#include "ltwrappr.h"

virtual L_INT LWia::AcquireToFile(uFlags, pSourceItem, pAcquireOptions, pnFilesCount, pppszFilePaths)

L_UINT32 uFlags;	/* optional flags */
L_VOID * pSourceItem;	/* scanner device paper source */
pLWIAACQUIREOPTIONS pAcquireOptions;	/* pointer to an optional acquire options structure */
L_INT * pnFilesCount;	/* optional pointer to a variable of type L_INT */
L_TCHAR *** pppszFilePaths;	/* optional pointer to a string buffer */

Acquires one or more images from a WIA source and saves them directly to file(s).

Parameter	Description
uFlags	Flag that determines certain actions of the WIA image acquisition selection dialog box. Possible values are:
	Value	Meaning
	0	Default behavior for the device image acquisition dialog box.
	L_WIA_DEVICE_DIALOG_SINGLE_IMAGE	[0x00000002] Restrict image selection to a single image in the device image acquisition dialog box. This flag is not available if you are using WIA version 2.0.
	L_WIA_SHOW_USER_INTERFACE	[0x00000003] Show the manufacturer's image acquisition dialog box.
	L_WIA_DEVICE_DIALOG_USE_COMMON_UI	[0x00000004] Use the system user interface (UI), if available, rather than the vendor-supplied UI. If the system UI is not available, the vendor UI is used.
pSourceItem	This parameter only takes place if you are acquiring from scanner device and while the L_WIA_SHOW_USER_INTERFACE flag is NOT set, through this parameter you can specify the scanners paper source (Feeder or Flatbed).
	This flag is optional, since if you are using WIA 1.0 then you can change the paper source by changing the WIA_DPS_DOCUMENT_HANDLING_SELECT property for the root item or by enumerating the available scanner items and pass the item you wish to scan from.
	If you are using WIA 2.0 then you have to enumerate the available scanner items and pass the item you wish to scan from or you can pass NULL and in this case the enumeration will be done internally and the first enumerated item will be used as the source item.

pAcquireOptions	Pointer to an optional acquires options structure that contains information the user can use to control the acquisition behavior from the WIA device.
	If the user passed NULL for this parameter, internal default values will be used.
pnFilesCount	Pointer to a variable of type L_INT to be updated with the number of the saved files.
pppszFilePaths	Pointer to string buffer to hold an array of the saved file paths. Used when the transfer mode is file.
	You can define a variable of type L_TCHAR** of size zero and pass the address of that variable to the acquire function.
	It is the user's responsibility to free the received file name array.

Returns

SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

This feature is available in LEADTOOLS version 16 or higher.

This function will acquire single or multiple images from the selected WIA device.

Make sure to call LWia::InitSession and then call any of the LWia::SelectDeviceDlg or LWia::SelectDevice functions before calling this function.

You can specify the parent window for the image acquisition dialog by calling the LScanner::SetWindow function.

This function will use the file transfer mode to acquire page(s) and save them directly to the hard disk using file name specified in the szFileName member of the LWIAACQUIREOPTIONS structure. If you are acquiring more than one page with the bSaveToOneFile member of the LWIAACQUIREOPTIONS structure set to FALSE, the WIA toolkit will automatically rename the saved files by adding (N) (where N is an incremented number generated to ensure that a file with the same name exists in the same path).

Since the file transfer mode is being used, overriding the LWia::AcquireFileCallback is optional (the callback will only be providing the saved file path and the percent completion of the file save process).

To cancel the acquire operation you need to override the LWia::AcquireFileCallBack function and return ERROR_USER_ABORT error code.

Note:	If the user set the L_WIA_SHOW_USER_INTERFACE flag, then he should be aware of the following point:
	Some of the previously set/changed user properties using any of the LWia::SetPropertyXXX or LWia::SetProperties functions will be overwritten by the Microsofts image acquisition dialog box, since this dialog sets its own initialization properties like the current intent (image type), selected area (left, top, width and height), paper source and duplex mode, etc.

So if the user wants to keep his changed properties then he should not set this flag to suppress the manufacturer's image acquisition dialog and acquire directly from the specified source item.

Note:

While running a Win32 version application that calls this function while specifying the pnFilesCount and pppszFilePaths parameters on Windows VISTA 64-Bit we have noticed that these two members will not be filled back with the required information and this is a known limitation from Microsofts WIA toolkit side.

Required DLLs and Libraries

LTWIA

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

See Also

Functions:	LWia::Acquire, LWia::AcquireSimple, LWia::InitSession, LWia::EndSession, Class Members
Topics:	How to Acquire from the WIA Source
	WIA Functionality: Property Functions

Example

class CMyWIA : public LWia
{
public:
   L_INT AcquireFileCallBack(L_TCHAR * pszFilename, L_UINT32 uPercent, L_UINT32 uFlags);
};
L_INT CMyWIA::AcquireFileCallBack(L_TCHAR * pszFilename, L_UINT32 uPercent, L_UINT32 uFlags)
{
   UNREFERENCED_PARAMETER(uPercent);
   L_TCHAR szMsg[MAX_PATH] = TEXT("");
   if(uFlags & L_WIA_ACQUIRE_END_OF_PAGE && pszFilename != NULL) // at this point the file should be saved to disk.
   {
      wsprintf(szMsg, 
               TEXT("Acquired file saved to the following path:\n\n%s"),
               pszFilename);
      MessageBox(NULL, szMsg, TEXT("Acquire To File"), MB_OK | MB_ICONINFORMATION);
   }
   return WIA_SUCCESS;
}
L_LTWIASAM_CLIB L_INT LWIA__AcquireToFileExample()
{
   L_INT nRet;
   LWIAACQUIREOPTIONS AcquireOpts;
   CMyWIA MyClass;
   nRet = MyClass.SelectDeviceDlg(WiaDeviceTypeDefault, 0);
   if(nRet != WIA_SUCCESS)
      return nRet;
   /* Initialize and fill the required fields from the LWIAACQUIREOPTIONS structure */
   memset(&AcquireOpts, 0, sizeof(LWIAACQUIREOPTIONS));
   AcquireOpts.uStructSize = sizeof(LWIAACQUIREOPTIONS);
   AcquireOpts.bAppend = FALSE;
   AcquireOpts.bOverwriteExisting = FALSE;
   AcquireOpts.bSaveToOneFile = FALSE;
   lstrcpy(AcquireOpts.szFileName, TEXT("C:\\Test.bmp"));
   nRet = MyClass.AcquireToFile(L_WIA_DEVICE_DIALOG_USE_COMMON_UI,
                                &AcquireOpts, 
                                NULL,
                                NULL,
                                NULL);
   if(nRet != WIA_SUCCESS)
      return nRet;
   return SUCCESS;
}