我想从我的应用程序中创建Code39编码的条形码。
我知道可以使用字体来实现,但我不想这样做,因为我必须在服务器上注册字体,而我曾经有过一些非常糟糕的经历。
在询问此问题之后,我制作了一个示例,可在答案中找到。
这是我的当前代码(带有很多注释):
Option Explicit On
Option Strict On
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Drawing.Bitmap
Imports System.Drawing.Graphics
Imports System.IO
Partial Public Class Barcode
Inherits System.Web.UI.Page
'Sebastiaan Janssen - 20081001 - TINT-30584
'Most of the code is based on this example:
'http://www.atalasoft.com/cs/blogs/loufranco/archive/2008/04/25/writing-code-39-barcodes-with-javascript.aspx-generation.aspx
'With a bit of this thrown in:
'http://www.atalasoft.com/cs/blogs/loufranco/archive/2008/03/24/code-39-barcode
Private _encoding As Hashtable = New Hashtable
Private Const _wideBarWidth As Short = 8
Private Const _narrowBarWidth As Short = 2
Private Const _barHeight As Short = 100
Sub BarcodeCode39()
_encoding.Add("*", "bWbwBwBwb")
_encoding.Add("-", "bWbwbwBwB")
_encoding.Add("$", "bWbWbWbwb")
_encoding.Add("%", "bwbWbWbWb")
_encoding.Add(" ", "bWBwbwBwb")
_encoding.Add(".", "BWbwbwBwb")
_encoding.Add("/", "bWbWbwbWb")
_encoding.Add("+", "bWbwbWbWb")
_encoding.Add("0", "bwbWBwBwb")
_encoding.Add("1", "BwbWbwbwB")
_encoding.Add("2", "bwBWbwbwB")
_encoding.Add("3", "BwBWbwbwb")
_encoding.Add("4", "bwbWBwbwB")
_encoding.Add("5", "BwbWBwbwb")
_encoding.Add("6", "bwBWBwbwb")
_encoding.Add("7", "bwbWbwBwB")
_encoding.Add("8", "BwbWbwBwb")
_encoding.Add("9", "bwBWbwBwb")
_encoding.Add("A", "BwbwbWbwB")
_encoding.Add("B", "bwBwbWbwB")
_encoding.Add("C", "BwBwbWbwb")
_encoding.Add("D", "bwbwBWbwB")
_encoding.Add("E", "BwbwBWbwb")
_encoding.Add("F", "bwBwBWbwb")
_encoding.Add("G", "bwbwbWBwB")
_encoding.Add("H", "BwbwbWBwb")
_encoding.Add("I", "bwBwbWBwb")
_encoding.Add("J", "bwbwBWBwb")
_encoding.Add("K", "BwbwbwbWB")
_encoding.Add("L", "bwBwbwbWB")
_encoding.Add("M", "BwBwbwbWb")
_encoding.Add("N", "bwbwBwbWB")
_encoding.Add("O", "BwbwBwbWb")
_encoding.Add("P", "bwBwBwbWb")
_encoding.Add("Q", "bwbwbwBWB")
_encoding.Add("R", "BwbwbwBWb")
_encoding.Add("S", "bwBwbwBWb")
_encoding.Add("T", "bwbwBwBWb")
_encoding.Add("U", "BWbwbwbwB")
_encoding.Add("V", "bWBwbwbwB")
_encoding.Add("W", "BWBwbwbwb")
_encoding.Add("X", "bWbwBwbwB")
_encoding.Add("Y", "BWbwBwbwb")
_encoding.Add("Z", "bWBwBwbwb")
End Sub
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
BarcodeCode39()
Dim barcode As String = String.Empty
If Not IsNothing(Request("barcode")) AndAlso Not (Request("barcode").Length = 0) Then
barcode = Request("barcode")
Response.ContentType = "image/png"
Response.AddHeader("Content-Disposition", String.Format("attachment; filename=barcode_{0}.png", barcode))
'TODO: Depending on the length of the string, determine how wide the image will be
GenerateBarcodeImage(250, 140, barcode).WriteTo(Response.OutputStream)
End If
End Sub
Protected Function getBCSymbolColor(ByVal symbol As String) As System.Drawing.Brush
getBCSymbolColor = Brushes.Black
If symbol = "W" Or symbol = "w" Then
getBCSymbolColor = Brushes.White
End If
End Function
Protected Function getBCSymbolWidth(ByVal symbol As String) As Short
getBCSymbolWidth = _narrowBarWidth
If symbol = "B" Or symbol = "W" Then
getBCSymbolWidth = _wideBarWidth
End If
End Function
Protected Overridable Function GenerateBarcodeImage(ByVal imageWidth As Short, ByVal imageHeight As Short, ByVal Code As String) As MemoryStream
'create a new bitmap
Dim b As New Bitmap(imageWidth, imageHeight, Imaging.PixelFormat.Format32bppArgb)
'create a canvas to paint on
Dim canvas As New Rectangle(0, 0, imageWidth, imageHeight)
'draw a white background
Dim g As Graphics = Graphics.FromImage(b)
g.FillRectangle(Brushes.White, 0, 0, imageWidth, imageHeight)
'write the unaltered code at the bottom
'TODO: truely center this text
Dim textBrush As New SolidBrush(Color.Black)
g.DrawString(Code, New Font("Courier New", 12), textBrush, 100, 110)
'Code has to be surrounded by asterisks to make it a valid Code39 barcode
Dim UseCode As String = String.Format("{0}{1}{0}", "*", Code)
'Start drawing at 10, 10
Dim XPosition As Short = 10
Dim YPosition As Short = 10
Dim invalidCharacter As Boolean = False
Dim CurrentSymbol As String = String.Empty
For j As Short = 0 To CShort(UseCode.Length - 1)
CurrentSymbol = UseCode.Substring(j, 1)
'check if symbol can be used
If Not IsNothing(_encoding(CurrentSymbol)) Then
Dim EncodedSymbol As String = _encoding(CurrentSymbol).ToString
For i As Short = 0 To CShort(EncodedSymbol.Length - 1)
Dim CurrentCode As String = EncodedSymbol.Substring(i, 1)
g.FillRectangle(getBCSymbolColor(CurrentCode), XPosition, YPosition, getBCSymbolWidth(CurrentCode), _barHeight)
XPosition = XPosition + getBCSymbolWidth(CurrentCode)
Next
'After each written full symbol we need a whitespace (narrow width)
g.FillRectangle(getBCSymbolColor("w"), XPosition, YPosition, getBCSymbolWidth("w"), _barHeight)
XPosition = XPosition + getBCSymbolWidth("w")
Else
invalidCharacter = True
End If
Next
'errorhandling when an invalidcharacter is found
If invalidCharacter Then
g.FillRectangle(Brushes.White, 0, 0, imageWidth, imageHeight)
g.DrawString("Invalid characters found,", New Font("Courier New", 8), textBrush, 0, 0)
g.DrawString("no barcode generated", New Font("Courier New", 8), textBrush, 0, 10)
g.DrawString("Input was: ", New Font("Courier New", 8), textBrush, 0, 30)
g.DrawString(Code, New Font("Courier New", 8), textBrush, 0, 40)
End If
'write the image into a memorystream
Dim ms As New MemoryStream
Dim encodingParams As New EncoderParameters
encodingParams.Param(0) = New EncoderParameter(Encoder.Quality, 100)
Dim encodingInfo As ImageCodecInfo = FindCodecInfo("PNG")
b.Save(ms, encodingInfo, encodingParams)
'dispose of the object we won't need any more
g.Dispose()
b.Dispose()
Return ms
End Function
Protected Overridable Function FindCodecInfo(ByVal codec As String) As ImageCodecInfo
Dim encoders As ImageCodecInfo() = ImageCodecInfo.GetImageEncoders
For Each e As ImageCodecInfo In encoders
If e.FormatDescription.Equals(codec) Then Return e
Next
Return Nothing
End Function
End Class
我不了解图书馆——我所做的所有条形码工作都是使用条形码字体完成的。如果您正在使用“3 of 9”格式,请查看免费的3-of-9。
3-of-9的注意事项:
确保所有文本都是大写的 在每个条形码的开头和结尾加上星号
虽然iTextSharp库主要用于创建PDF,但它还包含一个条形码生成库,其中包括Code39。
一旦你添加了对DLL的引用,使用起来非常简单:
Barcode39 code39 = new Barcode39();
code39.Code = "Whatever You're Encoding";
糟糕,那是C#,但你明白了。一旦创建,您可以以几乎任何图像格式呈现图像并按照您的意愿使用它。
你是在打印到一台标准打印机还是一台实际的条码打印机(zebra或datamax)? zebra和datamax都有自己的脚本语言 - 实际上更像是标记语言。分别是ZPL和DPL。我更喜欢zebra的,他们的文档更清晰。
如果你没有合法的条码打印机,我建议购买一台,并按照以下步骤操作...(相比尝试构建小图像块并绘制它们以模拟条码字体,这样做会更简洁)
两者都允许您具有很大的灵活性,并且可以让打印机处理创建实际的条码图像。
让你的程序通过FTP向打印机发送一个定制的包含要打印为条码的值的ZPL/DPL脚本。基本上,你只需要向打印机的IP地址“put”一个包含脚本的文本文件,然后打印机就会处理字体。
这里有一个关于如何在vb.net中生成Code39条形码的示例how to generate Code39 barcodes in vb.net。我现在已经测试过了,它可以正常工作。
Public Class code39
Private bitsCode As ArrayList
Public Sub New()
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
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("Le code doit être composé de 12 chiffres")
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
我更喜欢使用.net条形码生成器组件,而不是使用条形码字体。以下是一个用于创建Code 39条形码的VB.net示例。
Imports System.IO
Imports PQScan.BarcodeCreator
Namespace BarcodeGeneratorVB
Class Program
Private Shared Sub Main(args As String())
Dim barcode As New Barcode()
barcode.Data = "www.pqscan.com"
barcode.BarType = BarCodeType.Code39
barcode.Width = 300
barcode.Height = 100
barcode.CreateBarcode("code39-vb.jpeg")
End Sub
End Class
End Namespace
在我上一份工作中,我使用了几个不同的vb.net库。我们有一个库,后来换成了另一个库。我记不得它们的名字了(如果我再看到它们,我会认出来),但我知道两个都是付费的。在切换时,我们评估了几个不同的组件,我想其中包括一个免费的组件。我们是一个非常小的公司,非常注重成本,所以如果免费组件真的很好,你可以肯定我们会使用它(我想我们需要128b支持,而它只处理code39)。
我还记得我们换掉的原因是同时从.Net 1.1转移到了.Net 2.0,而第一个组件太慢了,使得过渡变得困难。
因此,总之,市面上有一些组件,但三年前它们都不怎么好用。希望其他人能提供一些实际的名称。