在线生成条形码的解决方案（39码、EAN-13）

public partial class ReceivablesFormView : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            string code = Get("6901028045575", 2, 60);

            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 = -1;//输入的校验码
            if (!Regex.IsMatch(s, @"^\d{12}$"))
            {
                if (s.Length != 13)
                {
                    return "字符串长度不正确！";
                }
                else if (!Regex.IsMatch(s, @"^\d{13}$"))
                {
                    return "存在不允许的字符！";
                }
                else
                {
                    checkcode_input = int.Parse(s[12].ToString());
                    s = s.Substring(0, 12);
                }
            }

            int sum_even = 0;//偶数位之和
            int sum_odd = 0;//奇数位之和

            for (int i = 0; i < 12; i++)
            {
                if (i % 2 == 0)
                {
                    sum_odd += int.Parse(s[i].ToString());
                }
                else
                {
                    sum_even += int.Parse(s[i].ToString());
                }
            }

            int checkcode = (10 - (sum_even * 3 + sum_odd) % 10) % 10;//校验码

            if (checkcode_input > 0 && 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 += "000000000101";

            string type = ean13type(s[0]);
            for (int i = 1; i < 7; i++)
            {
                result_bin += ean13(s[i], type[i - 1]);
            }
            result_bin += "01010";
            for (int i = 7; i < 13; i++)
            {
                result_bin += ean13(s[i], ‘C‘);
            }
            result_bin += "101000000000";

            string result_html = "";//HTML代码
            string color = "";//颜色
            int height_bottom = width * 5;
            foreach (char c in result_bin)
            {
                color = c == ‘0‘ ? "#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 * 9) + "px;text-align:center;\">" + s[0] + "</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 = 1; i < 7; i++)
            {
                result_html += "<div style=\"float:left;width:" + (width * 7) + "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 = 7; i < 13; i++)
            {
                result_html += "<div style=\"float:left;width:" + (width * 7) + "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 * 9) + "px;\"></div>";
            result_html += "<div style=\"clear:both\"></div>";

            return "<div style=\"background:#FFFFFF;padding:0px;font-size:" + (width * 10) + "px;font-family:‘楷体‘;\">" + result_html + "</div>";
        }
        private static string ean13(char c, char type)
        {
            switch (type)
            {
                case ‘A‘:
                    {
                        switch (c)
                        {
                            case ‘0‘: return "0001101";
                            case ‘1‘: return "0011001";
                            case ‘2‘: return "0010011";
                            case ‘3‘: return "0111101";//011101
                            case ‘4‘: return "0100011";
                            case ‘5‘: return "0110001";
                            case ‘6‘: return "0101111";
                            case ‘7‘: return "0111011";
                            case ‘8‘: return "0110111";
                            case ‘9‘: return "0001011";
                            default: return "Error!";
                        }
                    }
                case ‘B‘:
                    {
                        switch (c)
                        {
                            case ‘0‘: return "0100111";
                            case ‘1‘: return "0110011";
                            case ‘2‘: return "0011011";
                            case ‘3‘: return "0100001";
                            case ‘4‘: return "0011101";
                            case ‘5‘: return "0111001";
                            case ‘6‘: return "0000101";//000101
                            case ‘7‘: return "0010001";
                            case ‘8‘: return "0001001";
                            case ‘9‘: return "0010111";
                            default: return "Error!";
                        }
                    }
                case ‘C‘:
                    {
                        switch (c)
                        {
                            case ‘0‘: return "1110010";
                            case ‘1‘: return "1100110";
                            case ‘2‘: return "1101100";
                            case ‘3‘: return "1000010";
                            case ‘4‘: return "1011100";
                            case ‘5‘: return "1001110";
                            case ‘6‘: return "1010000";
                            case ‘7‘: return "1000100";
                            case ‘8‘: return "1001000";
                            case ‘9‘: return "1110100";
                            default: return "Error!";
                        }
                    }
                default: return "Error!";
            }
        }
        private static string ean13type(char c)
        {
            switch (c)
            {
                case ‘0‘: return "AAAAAA";
                case ‘1‘: return "AABABB";
                case ‘2‘: return "AABBAB";
                case ‘3‘: return "AABBBA";
                case ‘4‘: return "ABAABB";
                case ‘5‘: return "ABBAAB";
                case ‘6‘: return "ABBBAA";//中国
                case ‘7‘: return "ABABAB";
                case ‘8‘: return "ABABBA";
                case ‘9‘: return "ABBABA";
                default: return "Error!";
            }
        }
    }