Example 4: Acquire in Native mode

Example:  Start DTWAIN, Select a Source, Acquire all pages in Native mode.  Destroy the generated Device Independent Bitmaps.

#include "cdtwain.h"

#include <iostream>

using namespace DTWAIN;

using namespace std;

int main( )

{

  // Initialize DTWAIN - return if initialization does not work

  DTwainInterface TI;

  if ( !TI.IsValid( ) )

      return 0;

  // Declare a Source and assign the default TWAIN source to it

  DTwainSource Source = DTwainSource::Select( );

  if ( !Source.IsValid( ) )

     return 0;

  // Declare an acquisition object, and attach the source to it

  DTwainAcquirer Acq(Source);

  // Set the acquire type to Native

  Acq.SetAcquireType(TWAIN_ACQUIRENATIVE);

  // Set the maximum pages to acquire

  Acq.SetMaxPages( DTWAIN_ACQUIREALL );

  // Start the acquisition

  if ( !Acq.Acquire( ) )

  {

       // Acquisition failed

       return 0;

  }

  // get all the bitmaps (DIBs) that have been acquired

  DTwainAcquisitionArray AllDibs;

  Acq.GetAllAcquisitions( AllDibs );

  // AllDibs is a two-dimensional "array" (actually a two-dimensional vector).

  // The first index is the acquisition (which is an array of image data), the second index is the page

  // data itself.    The page data is stored in a DTwainImageData object.

  // So, if there are 2 acquisitions, and in acquisition 1 there are 3 pages,

  // and acquisition 2 has 1 page, the following is true:

  //

  // AllDibs[0][0] is acquisition 1, page 1's DIB (represented as a DTwainImageData object)

  // AllDibs[0][1] is acquisition 1, page 2's DIB (represented as a DTwainImageData object)

  // AllDibs[0][2] is acquisition 1, page 3's DIB (represented as a DTwainImageData object)

  // AllDibs[1][0] is acquisition 2, page 1's DIB (represented as a DTwainImageData object)

  //

  // To get a handle to the DIB for a particular acquisition and page

  // HANDLE hDib = AllDibs[0][1].GetImageData( ); // Handle to acquisition 1, page 2 image data.

  //

  // To get an array of DIBs for a particular acquisition:

  // DTwainImageDataArray DibsForAcq1 = AllDibs[0]; // All Dibs for acquisition 1

  //

  // To make sure that you are accessing a valid subscript, it is safer to first get the number of acquisitions and pages

  // instead of using operator [] first.

  cout << "The number of acquisitions attempted are " << AllDibs.size( ) << endl;

  // Now get the number of acquisitions.

  int nAcquisitions = AllDibs.size( );

  for ( int i = 0; i < nAcquisitions; ++i )

  {

     // Get array of DTwainImageData for acquisition i

    DTwainImageDataArray AData = AllDibs[i];

     cout << "For acquisition " << i << ", there are (is) " << AData.size( ) << " Dibs (pages)" << endl;

     // Now free the image data here.  This does it in a loop, but there are other ways to do

     // this without a loop.  Also note you can use the traditional array operator [] to access the

     // image information, but for illustrative purposes, we will use the STL iterator to loop through the

     // array of DTwainImageInfo

    DTwainImageDataArray::iterator start = AData.begin( );

     DTwainImageDataArray::iterator stop = AData.end( );

    DTwainImageData ImageData; // represents the raw image data for a single page

     while ( start != stop )

     {

         ImageData = *start;  // get the current DTwainImageData object

         HANDLE hDib = ImageData.GetImageData( );

         GlobalFree( hDib );  // Free the data here

         ++start;

     }

   }

}  // Twain is shut down automatically on exit