clsEAN13.vb

Imports System.Drawing
Imports System.Reflection
Imports log4net

Namespace Barcode

    Public Class clsEAN13
        Private Shared ReadOnly _log As ILog = LogManager.GetLogger(GetType(clsEAN13))

        Private bitsCode As ArrayList

        'http://www.vbforums.com/showthread.php?349118-EAN-13-CODE39-UPC-CODE128-Code-Bar-Generator

        Public Sub New()

            _log.Info("Starting EAN13 Tools DLL" & MethodBase.GetCurrentMethod().ToString())

            bitsCode = New ArrayList
            bitsCode.Add(New String(3) {"0001101", "0100111", "1110010", "000000"})
            bitsCode.Add(New String(3) {"0011001", "0110011", "1100110", "001011"})
            bitsCode.Add(New String(3) {"0010011", "0011011", "1101100", "001101"})
            bitsCode.Add(New String(3) {"0111101", "0100001", "1000010", "001110"})
            bitsCode.Add(New String(3) {"0100011", "0011101", "1011100", "010011"})
            bitsCode.Add(New String(3) {"0110001", "0111001", "1001110", "011001"})
            bitsCode.Add(New String(3) {"0101111", "0000101", "1010000", "011100"})
            bitsCode.Add(New String(3) {"0111011", "0010001", "1000100", "010101"})
            bitsCode.Add(New String(3) {"0110111", "0001001", "1001000", "010110"})
            bitsCode.Add(New String(3) {"0001011", "0010111", "1110100", "011010"})

        End Sub
        ''' <summary>
        ''' 12 Numbers to convert to EAN13
        ''' </summary>
        ''' <param name="Code">12 Numbers to convert to EAN13</param>
        ''' <returns></returns>
        Public Function Generate(ByVal Code As String) As Image
            Dim a As Integer = 0
            Dim b As Integer = 0
            Dim imgCode As Image
            Dim g As Graphics
            Dim i As Integer
            Dim bCode As Byte()
            Dim bitCode As Byte()
            Dim tmpFont As Font

            If Code.Length <> 12 Or Not IsNumeric(Code.Replace(".", "_").Replace(",", "_")) Then Throw New Exception("The code must be 12 numbers")

            ReDim bCode(12)
            For i = 0 To 11
                bCode(i) = CInt(Code.Substring(i, 1))
                If (i Mod 2) = 1 Then
                    b += bCode(i)
                Else
                    a += bCode(i)
                End If
            Next

            i = (a + (b * 3)) Mod 10
            If i = 0 Then
                bCode(12) = 0
            Else
                bCode(12) = 10 - i
            End If
            bitCode = getBits(bCode)

            tmpFont = New Font("times new roman", 14, FontStyle.Regular, GraphicsUnit.Pixel)
            imgCode = New Bitmap(110, 50)
            g = Graphics.FromImage(imgCode)
            g.Clear(Color.White)

            g.DrawString(Code.Substring(0, 1), tmpFont, Brushes.Black, 2, 30)
            a = g.MeasureString(Code.Substring(0, 1), tmpFont).Width

            For i = 0 To bitCode.Length - 1
                If i = 2 Then
                    g.DrawString(Code.Substring(1, 6), tmpFont, Brushes.Black, a, 30)
                ElseIf i = 48 Then
                    g.DrawString(Code.Substring(7, 5) & bCode(12).ToString, tmpFont, Brushes.Black, a, 30)
                End If

                If i = 0 Or i = 2 Or i = 46 Or i = 48 Or i = 92 Or i = 94 Then
                    If bitCode(i) = 1 Then 'noir
                        g.DrawLine(Pens.Black, a, 0, a, 40)
                        a += 1
                    End If
                Else
                    If bitCode(i) = 1 Then 'noir
                        g.DrawLine(Pens.Black, a, 0, a, 30)
                        a += 1
                    Else 'blanc
                        a += 1
                    End If
                End If
            Next
            g.Flush()
            Return imgCode
        End Function

        Private Function getBits(ByVal bCode As Byte()) As Byte()
            Dim i As Integer
            Dim res As Byte()
            Dim bits As String = "101"
            Dim cle As String = bitsCode(bCode(0))(3)
            For i = 1 To 6
                bits &= bitsCode(bCode(i))(CInt(cle.Substring(i - 1, 1)))
            Next
            bits &= "01010"
            For i = 7 To 12
                bits &= bitsCode(bCode(i))(2)
            Next
            bits += "101"
            ReDim res(bits.Length - 1)
            For i = 0 To bits.Length - 1
                res(i) = Asc(bits.Chars(i)) - 48
            Next
            Return res
        End Function

    End Class

End Namespace