[The ASP.NET] Display Code39 code (one-dimensional bar code) on page

Abstract: [ASP.NET] display Code39 code (one-dimensional bar code) on the page

After the brother company recently encountered just need to enter the string

Converted into dimensional bar code and displayed on the page

This brother should refer to the practice of many network

They are also similar

Step 1: establish code39.ashx

<%@ WebHandler Language="C#"  %>

using System;
using System.Web;
using System.Drawing;
using System.IO;

public class code39 : IHttpHandler
{
    public void ProcessRequest(HttpContext context)
    {
        string sCode = string.Empty;
        //清除该页输出缓存，设置该页无缓存   
        context.Response.Buffer = true;
        context.Response.ExpiresAbsolute = System.DateTime.Now.AddMilliseconds(0);
        context.Response.Expires = 0;
        context.Response.CacheControl = "no-cache";
        context.Response.AppendHeader("Pragma", "No-Cache");
        //将Code39条码写入内存流，并将其以 "image/Png" 格式输出   
        MemoryStream oStream = new MemoryStream();
        try
        {
            Bitmap oBmp = GetCode39(context.Request.QueryString["id"]);
            oBmp.Save(oStream, System.Drawing.Imaging.ImageFormat.Png);
            oBmp.Dispose();
            context.Response.ClearContent();
            context.Response.ContentType = "image/Png";
            context.Response.BinaryWrite(oStream.ToArray());
        }
        finally
        {
            //释放资源   
            oStream.Dispose();
        }
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }

    private Bitmap GetCode39(string strSource)
    {
        int x = 5; //左边界
        int y = 0; //上边界
        int WidLength = 2; //粗BarCode长度
        int NarrowLength = 1; //细BarCode长度
        int BarCodeHeight = 24; //BarCode高度
        int intSourceLength = strSource.Length;
        string strEncode = "010010100"; //编码字符串 初值为 起始符号 *

        string AlphaBet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%*"; //Code39的字母

        string[] Code39 = //Code39的各字母对应码
        {
             ///* 0 */ "000110100",  
             ///* 1 */ "100100001",  
             ///* 2 */ "001100001",  
             ///* 3 */ "101100000",
             ///* 4 */ "000110001",  
             ///* 5 */ "100110000",  
             ///* 6 */ "001110000",  
             ///* 7 */ "000100101",
             ///* 8 */ "100100100",  
             ///* 9 */ "001100100",  
             ///* A */ "100001001",  
             ///* B */ "001001001",
             ///* C */ "101001000",  
             ///* D */ "000011001",  
             ///* E */ "100011000",  
             ///* F */ "001011000",
             ///* G */ "000001101",  
             ///* H */ "100001100",  
             ///* I */ "001001100",  
             ///* J */ "000011100",
             ///* K */ "100000011",  
             ///* L */ "001000011",  
             ///* M */ "101000010",  
             ///* N */ "000010011",
             ///* O */ "100010010",  
             ///* P */ "001010010",  
             ///* Q */ "000000111",  
             ///* R */ "100000110",
             ///* S */ "001000110",  
             ///* T */ "000010110",  
             ///* U */ "110000001",  
             ///* V */ "011000001",
             ///* W */ "111000000",  
             ///* X */ "010010001",  
             ///* Y */ "110010000",  
             ///* Z */ "011010000",
             ///* - */ "010000101",  
             ///* . */ "110000100",  
             ///*' '*/ "011000100",
             ///* $ */ "010101000",
             ///* / */ "010100010",  
             ///* + */ "010001010",  
             ///* % */ "000101010",  
             ///* * */ "010010100"  
        };
        
        strSource = strSource.ToUpper();
        //实践图片
        Bitmap objBitmap = new Bitmap(((WidLength * 3 + NarrowLength * 7) * (intSourceLength + 2)) + (x * 2), BarCodeHeight + (y * 2));
        Graphics objGraphics = Graphics.FromImage(objBitmap); //声明GDI+绘图界面
        //填上底色
        objGraphics.FillRectangle(Brushes.White, 0, 0, objBitmap.Width, objBitmap.Height);

        for (int i = 0; i < intSourceLength; i++)
        {
            //检查是否有非法符
            if (AlphaBet.IndexOf(strSource[i]) == -1 || strSource[i] == '*')
            {
                objGraphics.DrawString("含有非法符", SystemFonts.DefaultFont, Brushes.Red, x, y);
                return objBitmap;
            }
            //查表编码
            strEncode = string.Format("{0}0{1}", strEncode, Code39[AlphaBet.IndexOf(strSource[i])]);
        }

        strEncode = string.Format("{0}0010010100", strEncode); //补上结束符号 *

        int intEncodeLength = strEncode.Length; //编码后长度
        int intBarWidth;

        for (int i = 0; i < intEncodeLength; i++) //依码画出Code39 BarCode
        {
            intBarWidth = strEncode[i] == '1' ? WidLength : NarrowLength;
            objGraphics.FillRectangle(i % 2 == 0 ? Brushes.Black : Brushes.White, x, y, intBarWidth, BarCodeHeight);
            x += intBarWidth;
        }
        return objBitmap;
    }
}

Step 2: Use call

// 前端写法,加入image为显式条码用,textbox为输入字符串



  
  

   


  
   

  
   
    


// 后台,将Image1的ImageUrl指定为code39.ashx,并使用网页传值方式得到回传值
protected void Button4_Click(object sender, EventArgs e)
{
    string sUrl = "~/code39.ashx?https://az787680.vo.msecnd.net/user/aquarius6913/1304/2013481002500.JPG" rel="lightbox">
    
    


                    
    


    


    


    


    


    

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 原文:大专栏  [ASP.NET] 在页面上显示Code39码(一维条码)