[ASP.NET] 在页面上显示Code39码(一维条码)

摘要:[ASP.NET] 在页面上显示Code39码(一维条码)

最近小弟公司刚好遇到有需要输入字符串后

转换成维条码并显示在页面上

应此小弟参考一下网络许多做法

也都大同小异

Step 1: 建立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:调用使用

// 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)
 

						


						

						原文地址：https://www.cnblogs.com/petewell/p/11490050.html