FAQ: TBarCode DLL

Instead of drawing directly you can build your own data structure (e.g. a Pixel map) during Callback. You can pass a custom pointer to the Callback function and use this pointer to add the pixel pattern to your structure (in a format as desired).

First set the pointer to your structure or memory block with this function:

BCSetCBData(t_BarCode* pBarCode, LPVOID customData)

This pointer is handled to you in the Callback function:

ERRCODE CALLBACK CustomDrawRow(VOID* customData, t_BarCode* barcode, 
HDC drawDC, HDC targetDC, DOUBLE x, DOUBLE y, DOUBLE width, DOUBLE height);

Now you can store the pattern info (row by row) into your own structure or memory block. After drawing has been finished you have it all in your structure.

TBarCode V6

'callback function
Public Function MyDrawRow ( ByRef pMyData As Long, 
          ByVal pBarCode As UIntPtr, ByVal hDC As IntPtr, 
          ByVal hTargetDC As IntPtr, 
          ByRef pRect As Rectangle) As UInt32
   Dim strTempo As String
   strTempo = TBC6.BCGetMetaData(pBarCode)
   Return Convert.ToUInt32(0)
End Function

'setting the address of the callback function 
Public cb As TBC6.Callback
   cb = AddressOf MyDrawRow
   eCode = TBC6.BCSetFuncDrawRow(hBarcode, cb, pData)

'required declarations 
Declare Ansi Function BCDrawCB Lib "TBarCode6.ocx" ( _
          ByRef hBarcode As UIntPtr, _
          ByVal hDC As IntPtr, _
          ByRef pRect As Rectangle, _
          ByVal func As Callback, _
          ByVal func As Callback, _
          ByVal pData As IntPtr ) As Int32

Declare Ansi Function BCGetMetaData Lib "TBarCode6.ocx" ( _
           ByVal hBarcode As UIntPtr ) As String

DrawBarcode (HDC hDC, long xpos, long ypos)
{
    RECT  hRect;
    long  lHRHeight = 0;

    ypos += GetFullHeight();
    hRect.left     = xpos;
    hRect.top      = ypos;
    hRect.right    = hRect.left   + width;
    hRect.bottom   = hRect.top    + height;

    HDC memDC;
    HBITMAP memBMP, oldBMP;
    int width, height;
    RECT draw;

    width = abs(hRect.right - hRect.left);
    height = abs (hRect.bottom - hRect.top);

    draw.left = 0;
    draw.bottom = height;
    draw.top = 0;
    draw.right = width;

    memDC = CreateCompatibleDC(hDC);
    memBMP = CreateCompatibleBitmap(hDC, width, height);

    oldBMP = (HBITMAP) SelectObject(memDC, memBMP);

    if (S_OK = BCDraw(pBarcode, memDC, &draw))
    {
        // scale / copy to target DC      
        BitBlt(hDC, hRect.left, hRect.top, width, 
                 height, memDC, 0, 0, SRCCOPY);
        SelectObject(memDC, oldBMP);
    }      
    DeleteObject(memBMP);
    DeleteDC(memDC);
}

Create a LOGFONT structure and set it with the BCSetLogFont function.

Function BCSetLogFont
(
  const pBarCode:t_BarCode; // IN : Ptr To Barcode-Definition
  lf:LOGFONT  // IN : TLogFont (TFont) structure
):TErrCode; 
external 'TBarCode8.dll';

Here is a sample of a LOGFONT structure. To adjust the font size, you must change the parameter lfHeight in the structure.

var
  lf:TLogFont;
begin
  lf.lfHeight := 24;          {char height in pixels    }
  lf.lfWidth := 12;           {char width in pixels     }
  lf.lfEscapement := 0;       {orientation of next char }
  lf.lfOrientation := 0;      {orientation of first char}
  lf.lfWeight := FW_NORMAL;   {normal thickness         }
  lf.lfItalic := 0;           {not italic characters    }
  lf.lfUnderline := 0;        {not underlined characters}
  lf.lfStrikeOut := 0;        {not strikeout characters }
  lf.lfCharSet := OEM_CHARSET;{OEM character set        }
  lf.lfOutPrecision := 0;     {default output precision }
  lf.lfClipPrecision := 0;    {default clipping precision}
  lf.lfQuality := DEFAULT_QUALITY; {default scaling quality}
  lf.lfPitchAndFamily := FF_SCRIPT;{default pitch,
                                    script font family   }
  lstrcpy(lf.lfFaceName,'Arial'+chr(0)); {script typeface}

For more information about LOGFONT visit http://msdn.microsoft.com/en-us/library/ms533931(VS.85).aspx

Data for QR-Code can be treated either as a sequence of Bytes or as a sequence of SHIFT JIS characters.

Beside SHIFT JIS so-called “ECIs” can be used to switch to different Code-Pages - but ECIs are often unsupported by decoder software.

The default character set of QR-Code is Shift JIS according to AIM International ITS/97-001 QR Code Symbology Specification. In order to use the QR-Code Kanji Compaction Mode, the input for the encoder must be in a specific character set:

TBarCode DLL, TBarCode/X Library Version 7

Input must be in Multi Byte Character Set Format SHIFT JIS (not UTF-8, not Unicode!).

• Single Bytes characters are encoded according to JIS X 0201.
• Double Byte characters are encoded according to Shift JIS X 0208.

TBarCode DLL, TBarCode/X Library Version 8

Input must be in Unicode (UTF-16 in Windows Version and UTF-32/UCS-4 in Linux/UNIX Version).

Double Byte characters contained in the Shift JIS X 0208-1990 table can be compacted in QR-Code 13-Bit Mode. To enable the compaction in the TBarCode Library you have to call the function

BCSet_QR_KanjiChineseCompaction ()

Here are some links to background information about Kanji and Unicode:

• http://www.rikai.com/library/kanjitables/kanji_codes.sjis.shtml
• http://en.wikipedia.org/wiki/Shift-JIS
• http://www.microsoft.com/globaldev/reference/dbcs/932.mspx (SHIFT JIS – Unicode Table)
• http://www.tamasoft.co.jp/en/general-info/sjis.html