The table below lists the functions exported from this encoder DLL.

These are the functions directly exported from the DLL. We provide wrapper modules for some programming environments, such as Visual Basic 6 and .Net. The interfaces exposed from these wrapper modules are different from the ones listed in this table.

To use a DLL in a C/CC++ project, it is recommended that you load the DLL dynamically into the process, obtain address of the function, and invoke the function through that address. After calling the DLL function, your program unloads the DLL. In this way, it is not necessary to link your application with an import library.

The example below illustrates using run-time dynamic linking when calling the encoder DLL.

#include <windows.h>
#include <stdio.h>
int main(int argc, char* argv[])
{
  HINSTANCE hInstance = ::LoadLibrary("MoroviaDataBarFontEncoder.dll");
  int errorCode = 0;
  if (!hInstance) {
    fprintf(stderr, "Can not load MoroviaDataBarFontEncocer.dll.\n");
    errorCode = 100;
    goto LABEL_EXIT;
  }

  typedef int (__stdcall*ENCODE_FUNC_TYPE3)(const char*, char*, unsigned int);
  typedef int (__stdcall*ENCODE_FUNC_TYPE4)(const char*, unsigned int, 
          char*, unsigned int);

  ENCODE_FUNC_TYPE3 pFuncDataBar14 = (ENCODE_FUNC_TYPE3)::GetProcAddress(hInstance, 
                                            "DataBar14");
  if (!pFuncDataBar14) {
    fprintf(stderr, "Invalid DLL.");
    errorCode = 101;
    goto LABEL_EXIT;
  }

  const char* input = "0123456789123";
  char buffer[512];
  int rc = (*pFuncDataBar14)(input, buffer, 512);
  if ( rc > 0 ) {
    fprintf(stdout, "DataBar-14 barcode string for data (%s) is %s.\n",
      input, buffer);
  } else {
    fprintf(stderr, "Invalid data");
    errorCode = 101;
    goto LABEL_EXIT;
  }

  ENCODE_FUNC_TYPE4 pFuncDataBarExp = 
              (ENCODE_FUNC_TYPE4)::GetProcAddress(hInstance, "DataBarExpanded");
  if (!pFuncDataBarExp) {
    fprintf(stderr, "Invalid DLL.");
    errorCode = 101;
    goto LABEL_EXIT;
  }
  input = "(01)1234567890(15)990210";
  rc = (*pFuncDataBarExp)(input, 4, buffer, 512);
  if ( rc > 0 ) {
    fprintf(stdout, "DataBar Expanded barcode string for data (%s) is %s.\n",
      input, buffer);
  } else {
    fprintf(stderr, "Invalid data");
    errorCode = 101;
    goto LABEL_EXIT;
  }

LABEL_EXIT:
  ::FreeLibrary(hInstance);
  return errorCode;
} 

The code above first calls Win32 API LoadLibrary to load the DLL into the process memory. For improving readability, the code defines two function pointer types: ENCODE_FUNC_TYPE3, which takes three arguments, and ENCODE_FUNC_TYPE4, which takes four arguments. The address of the DLL exported function is then retrieved by calling GetProcAddress and casted to an corresponding function pointer instance. Subsequently the encoder function is invoked through this function pointer.

You can use the same Morovia.DataBarFontDLL.bas module from the one in Office examples. Copy the file into your project directory, and add it to the project. For the function prototypes, see Table 5.1, “List of VBA Functions (Morovia.DataBarFontDLL.bas)”.

When printing GS1 DataBar Stacked Omnidirectional and GS1 DataBar Expanded Stacked barcodes, you need to call Split function to divide barcode string into an array of lines. Then print the lines one by one. Visual Basic does not handle line returns automatically.

 'To print the barcode, we recommend using the built-in Printer object
 'Do not print to a picture box and transfer it to printer. That results
 'in a low quality barcode.
 
 'You can change it to other values to adjust the barcode size.
 Printer.FontSize = 12
 Printer.FontName = "MRV DataBar 34X"
 
 'We use inch as measurement unit here.
 Printer.ScaleMode = vbInches
 
 'We want to print the barcode at point (1.5 inch, 3 inch)
 'Note - printer usually has a margin 0.25" at four directions.
 'You may consider this fact when you set the printer cursor
 Dim StartX, StartY As Double
 StartX = 1.5
 StartY = 3#
 Printer.CurrentX = StartX
 Printer.CurrentY = StartY
 
 'The Priner always go back to the left edge of the page after
 'executing a print statement. Unless we print the barcode to
 'the left ledge of the page,
 'we have to parse the barcode string into lines, and print
 'them one by one.
 'Fortunately, VB provides a nice helper function for this purpose.
 Dim separator As String
 Dim lines() As String
 separator = vbCrLf
 lines() = Split(lblBarcodeString.Caption, separator)
 
 'Now we do the actual print line by line
 Dim i As Integer
 
 For i = 0 To UBound(lines)
   Printer.Print lines(i)
   'Note: the Printer always go back to the beginning of the next line
   'after executing Print. We need to set CurrentX every time after
   'printing a line
   Printer.CurrentX = StartX
 Next
 
 'EndDoc must be called to actual print
 Printer.EndDoc 

In Perl, you can use Win32::API module, the Perl Win32 API Import Facility to call a Windows DLL function. The code below demonstrates how you can call a DLL function from a Perl script:

#!/usr/bin/perl -w
use strict;
use Win32::API;

my $DataBarStacked = Win32::API->new('MoroviaDataBarFontEncoder', 
                'DataBarStacked',
                'PPN', 'I');
my $DataToEncode = "1234567890123";
my $Buffer = " " x 512;  # allocate a 512-byte buffer

$DataBarStacked->Call($DataToEncode, $Buffer, 512);
printf("Barcode String is %s\n", $Buffer); 

For .Net programmers we prepared a wrapper class called DataBarFontEncoder. Add file Morovia.DataBarFontEncoder.cs into your project, and you can call the methods as if they are local. Note that the prototypes of the methods are different from the one listed in Table 7.1, “Encoder Functions (MoroviaDataBarEncoder.dll)”. They are very similiar to the VBA functions in Table 5.1, “List of VBA Functions (Morovia.DataBarFontDLL.bas)”.

In the following code snippet, DataBarStacked method is invoked to get the barcode string for DataBar Stacked barcode with data 1234567890123 encoded. The second part of the code gets the full string (with check digit) of a GTIN-14 number.

DataBarFontEncoder encoder = new DataBarFontEncoder();
string DataToEncode = @"1234567890123";
string result = encoder.DataBarStacked(DataToEncode);
Console.WriteLine("BarcodeString for {0} is {1}",
  DataToEncode,
  result);

result = encoder.Mod10(DataToEncode);
Console.WriteLine("Full GTIN number (with check digit) is {0}",
  result); 

Most programming environments support calling native Windows DLL directly. You usually declare the functions exported from the DLL first, then use them as if they are local functions.