Y2J

最近小弟公司剛好遇到有需要輸入字串後

轉換成維條碼並顯示在頁面上

應此小弟參考一下網路許多做法

也都大同小異

Step 1: 建立code39.ashx

 

<%@ WebHandler Language="C#" Class="code39" %>

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

public class code39 : IHttpHandler
{
    public void ProcessRequest(HttpContext context)
    {
        string sCode = string.Empty;
        //清除該頁輸出緩存，設置該頁無緩存   
        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");
        //將Code39條碼寫入記憶體流，並將其以 "image/Png" 格式輸出   
        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
        {
            //釋放資源   
            oStream.Dispose();
        }
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }

    private Bitmap GetCode39(string strSource)
    {
        int x = 5; //左邊界
        int y = 0; //上邊界
        int WidLength = 2; //粗BarCode長度
        int NarrowLength = 1; //細BarCode長度
        int BarCodeHeight = 24; //BarCode高度
        int intSourceLength = strSource.Length;
        string strEncode = "010010100"; //編碼字串 初值為 起始符號 *

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

        string[] Code39 = //Code39的各字母對應碼
        {
             /**//* 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();
        //實作圖片
        Bitmap objBitmap = new Bitmap(((WidLength * 3 + NarrowLength * 7) * (intSourceLength + 2)) + (x * 2), BarCodeHeight + (y * 2));
        Graphics objGraphics = Graphics.FromImage(objBitmap); //宣告GDI+繪圖介面
        //填上底色
        objGraphics.FillRectangle(Brushes.White, 0, 0, objBitmap.Width, objBitmap.Height);

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

        strEncode = string.Format("{0}0010010100", strEncode); //補上結束符號 *

        int intEncodeLength = strEncode.Length; //編碼後長度
        int intBarWidth;

        for (int i = 0; i < intEncodeLength; i++) //依碼畫出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:呼叫使用

 

// 前端寫法,加入image為顯式條碼用,textbox為輸入字串
<br />
<asp:Image ID="Image1" runat="server" />
<br />
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<asp:Button ID="Button4" runat="server" Text="產生條碼" onclick="Button4_Click" />


// 後台,將Image1的ImageUrl指定為code39.ashx,並使用網頁傳值方式得到回傳值
protected void Button4_Click(object sender, EventArgs e)
{
    string sUrl = "~/code39.ashx?id=" + TextBox2.Text.Trim();
    Image1.ImageUrl = sUrl;
}

 

 

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