ASP.net(c#)生成条形码

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Response.Write(bar_code(" [url]www.sosuo8.com[/url]", 100, 1, 2));
    }
    public string bar_code(object str, int ch, int cw, int type_code)
    {
        //str:输入的字符串;ch:要显示条形码的高度;cw:要显示条形码的宽度;type_code:代码类型
        string strTmp = str.ToString();
        string code = strTmp;
        // ToLower()将string转化成小写形式的副本，返回是使用指定区域的性的大小写规则。
        strTmp = strTmp.ToLower();
        int height = ch;
        int width = cw;

        //将传入的参数进行转化。
        strTmp = strTmp.Replace("0", "_|_|__||_||_|"); ;
        strTmp = strTmp.Replace("1", "_||_|__|_|_||");
        strTmp = strTmp.Replace("2", "_|_||__|_|_||");
        strTmp = strTmp.Replace("3", "_||_||__|_|_|");
        strTmp = strTmp.Replace("4", "_|_|__||_|_||");
        strTmp = strTmp.Replace("5", "_||_|__||_|_|");
        strTmp = strTmp.Replace("7", "_|_|__|_||_||");
        strTmp = strTmp.Replace("6", "_|_||__||_|_|");
        strTmp = strTmp.Replace("8", "_||_|__|_||_|");
        strTmp = strTmp.Replace("9", "_|_||__|_||_|");
        strTmp = strTmp.Replace("a", "_||_|_|__|_||");
        strTmp = strTmp.Replace("b", "_|_||_|__|_||");
        strTmp = strTmp.Replace("c", "_||_||_|__|_|");
        strTmp = strTmp.Replace("d", "_|_|_||__|_||");
        strTmp = strTmp.Replace("e", "_||_|_||__|_|");
        strTmp = strTmp.Replace("f", "_|_||_||__|_|");
        strTmp = strTmp.Replace("g", "_|_|_|__||_||");
        strTmp = strTmp.Replace("h", "_||_|_|__||_|");
        strTmp = strTmp.Replace("i", "_|_||_|__||_|");
        strTmp = strTmp.Replace("j", "_|_|_||__||_|");
        strTmp = strTmp.Replace("k", "_||_|_|_|__||");
        strTmp = strTmp.Replace("l", "_|_||_|_|__||");
        strTmp = strTmp.Replace("m", "_||_||_|_|__|");
        strTmp = strTmp.Replace("n", "_|_|_||_|__||");
        strTmp = strTmp.Replace("o", "_||_|_||_|__|");
        strTmp = strTmp.Replace("p", "_|_||_||_|__|");
        strTmp = strTmp.Replace("r", "_||_|_|_||__|");
        strTmp = strTmp.Replace("q", "_|_|_|_||__||");
        strTmp = strTmp.Replace("s", "_|_||_|_||__|");
        strTmp = strTmp.Replace("t", "_|_|_||_||__|");
        strTmp = strTmp.Replace("u", "_||__|_|_|_||");
        strTmp = strTmp.Replace("v", "_|__||_|_|_||");
        strTmp = strTmp.Replace("w", "_||__||_|_|_|");
        strTmp = strTmp.Replace("x", "_|__|_||_|_||");
        strTmp = strTmp.Replace("y", "_||__|_||_|_|");
        strTmp = strTmp.Replace("z", "_|__||_||_|_|");
        strTmp = strTmp.Replace("-", "_|__|_|_||_||");
        strTmp = strTmp.Replace("*", "_|__|_||_||_|");
        strTmp = strTmp.Replace("/", "_|__|__|_|__|");
        strTmp = strTmp.Replace("%", "_|_|__|__|__|");
        strTmp = strTmp.Replace("+", "_|__|_|__|__|");
        strTmp = strTmp.Replace(".", "_||__|_|_||_|");
        strTmp = strTmp.Replace("_", "<span   style='height:" + height + ";width:" + width + ";background:#FFFFFF;'></span>");
        strTmp = strTmp.Replace("|", "<span   style='height:" + height + ";width:" + width + ";background:#000000;'></span>");

        if (type_code == 1)
        {
            return strTmp + "<BR>" + code;
        }
        else
        {
            return strTmp;
        }
    }  
}