在线生成条形码的解决方案（39码、EAN-13）

感谢博主：转自：http://xoyozo.eyuyao.com/blog/barcode.html

public partial class ReceivablesFormView : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string code = Get("", , );

            this.barcode.InnerHtml = code;
        }

        /// <summary>
        /// 获取 EAN-13 条形码（HTML 版）
        /// </summary>
        /// <param name="s">欲编码的字符串</param>
        /// <param name="width">单个条形宽（px）</param>
        /// <param name="height">条形高（px）</param>
        /// <returns></returns>
        public static string Get(string s, int width, int height)
        {
            int checkcode_input = -;//输入的校验码
            if (!Regex.IsMatch(s, @"^\d{12}$"))
            {
                if (s.Length != )
                {
                    return "字符串长度不正确！";
                }
                else if (!Regex.IsMatch(s, @"^\d{13}$"))
                {
                    return "存在不允许的字符！";
                }
                else
                {
                    checkcode_input = int.Parse(s[].ToString());
                    s = s.Substring(, );
                }
            }

            int sum_even = ;//偶数位之和
            int sum_odd = ;//奇数位之和

            for (int i = ; i < ; i++)
            {
                if (i %  == )
                {
                    sum_odd += int.Parse(s[i].ToString());
                }
                else
                {
                    sum_even += int.Parse(s[i].ToString());
                }
            }

            int checkcode = ( - (sum_even *  + sum_odd) % ) % ;//校验码

            if (checkcode_input >  && checkcode_input != checkcode)
            {
                return "输入的校验码错误！";
            }

            s += checkcode;//变成13位

            // 000000000101左侧42个01010右侧35个校验7个101000000000
            // 6        101左侧6位 01010右侧5位 校验1位101000000000

            string result_bin = "";//二进制串
            result_bin += "";

            string type = ean13type(s[]);
            for (int i = ; i < ; i++)
            {
                result_bin += ean13(s[i], type[i - ]);
            }
            result_bin += "";
            for (int i = ; i < ; i++)
            {
                result_bin += ean13(s[i], 'C');
            }
            result_bin += "";

            string result_html = "";//HTML代码
            string color = "";//颜色
            int height_bottom = width * ;
            foreach (char c in result_bin)
            {
                color = c == '' ? "#FFFFFF" : "#000000";
                result_html += "<div style=\"width:" + width + "px;height:" + height + "px;float:left;background:" + color + ";\"></div>";
            }
            result_html += "<div style=\"clear:both\"></div>";

            result_html += "<div style=\"float:left;color:#000000;width:" + (width * ) + "px;text-align:center;\">" + s[] + "</div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#000000;\"></div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#FFFFFF;\"></div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#000000;\"></div>";
            for (int i = ; i < ; i++)
            {
                result_html += "<div style=\"float:left;width:" + (width * ) + "px;color:#000000;text-align:center;\">" + s[i] + "</div>";
            }
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#FFFFFF;\"></div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#000000;\"></div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#FFFFFF;\"></div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#000000;\"></div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#FFFFFF;\"></div>";
            for (int i = ; i < ; i++)
            {
                result_html += "<div style=\"float:left;width:" + (width * ) + "px;color:#000000;text-align:center;\">" + s[i] + "</div>";
            }
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#000000;\"></div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#FFFFFF;\"></div>";
            result_html += "<div style=\"float:left;width:" + width + "px;height:" + height_bottom + "px;background:#000000;\"></div>";
            result_html += "<div style=\"float:left;color:#000000;width:" + (width * ) + "px;\"></div>";
            result_html += "<div style=\"clear:both\"></div>";

            return "<div style=\"background:#FFFFFF;padding:0px;font-size:" + (width * ) + "px;font-family:'楷体';\">" + result_html + "</div>";
        }
        private static string ean13(char c, char type)
        {
            switch (type)
            {
                case 'A':
                    {
                        switch (c)
                        {
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";//
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            default: return "Error!";
                        }
                    }
                case 'B':
                    {
                        switch (c)
                        {
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";//
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            default: return "Error!";
                        }
                    }
                case 'C':
                    {
                        switch (c)
                        {
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            case '': return "";
                            default: return "Error!";
                        }
                    }
                default: return "Error!";
            }
        }
        private static string ean13type(char c)
        {
            switch (c)
            {
                case '': return "AAAAAA";
                case '': return "AABABB";
                case '': return "AABBAB";
                case '': return "AABBBA";
                case '': return "ABAABB";
                case '': return "ABBAAB";
                case '': return "ABBBAA";//中国
                case '': return "ABABAB";
                case '': return "ABABBA";
                case '': return "ABBABA";
                default: return "Error!";
            }
        }
    }