Barcodes...

Frankly speaking I am not familiar with barcode algorithm, but I think the idea is a following: each symbol is represented with some unique sequence of lines and gaps of variable width. I believe that these mappings are formalized with some industry standard, so as soon as you find it, you can write something like this:

    Dim objBitmap As New Bitmap
    objBitmap.CreateNew 300, 300, Format24bppRgb
    objBitmap.Graphics.Brush.PrimaryColor = ColorBlack
    
    Dim str As String
    str = "abc"
    
    Dim InitialX, InitialY, BarHeight
    
    InitialX = 20
    InitialY = 10
    BarHeight = 50
    
    Dim I As Long
    Dim X As Long
    X = InitialX
    For I = 1 To Len(str)
       Select Case Mid(str, I, 1)
        Case "a"
           objBitmap.Graphics.DrawRectangle X, InitialY, 1, BarHeight, True, False
           X = X + 3
           objBitmap.Graphics.DrawRectangle X, InitialY, 3, BarHeight, True, False
           X = X + 8
        Case "b"
           objBitmap.Graphics.DrawRectangle X, InitialY, 2, BarHeight, True, False
           X = X + 5
           objBitmap.Graphics.DrawRectangle X, InitialY, 1, BarHeight, True, False
           X = X + 4
           objBitmap.Graphics.DrawRectangle X, InitialY, 4, BarHeight, True, False
           X = X + 7
           
        '...
           
       End Select
    Next I

Of course, actual values for X = X + ... and objBitmap.Graphics.DrawRectangle X, InitialY, ..., BarHeight should be defined with a standard.

This is an extremely rough example. On practice, if I implemented this algorithm, I would create a function which draws several lines accepting the following parameters:

• Bitmap (or even better Graphics)

• Initial position (X from this sample)

• Array of line widths and array of gap width (maybe combined - even are lines, odd are gaps).

Of course it should return modified X.

The "map" function I would implement as an array of widths arrays. As index of this array I would use ASCII code of the character that is defined widths array stored at this item. For example symbol "A" will be described with items stored at 65 position, etc. This code would be more easy-to-read and maintain. Besides referring item in array by index will work much faster than Select Case construction.

Probably there some other more efficient implementation available, however at first sight it should be good solution.

Hopefully it will help.

Edited by user Monday, December 24, 2007 5:02:49 PM(UTC)  | Reason: Not specified