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("www.sosuo8.com", 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;
}
} 
}