public static int[] GetImagePos(string str)

        {

            str = str.Replace("$", " ");

            str = Regex.Replace(str, @"(?!<img.+?>)<.+?>", "");

            str = Regex.Replace(str, @"<img\b[^>]*>", "$");

            int startPos = 0;

            int foundPos = -1;

            int count = 0;

            List<int> foundItems = new List<int>();

            do

            {

                foundPos = str.IndexOf("$", startPos);

                if (foundPos > -1)

                {

                    startPos = foundPos + 1;

                    count++;

                    foundItems.Add(foundPos);

                }

            } while (foundPos > -1 && startPos < str.Length);

            return ((int[])foundItems.ToArray());

        }

        /// <summary>

        /// 获取Img的路径

        /// </summary>

        /// <param name="htmlText">Html字符串文本</param>

        /// <returns>以数组形式返回图片路径</returns>

        public static string[] GetHtmlImageUrlList(string htmlText)

        {

            Regex regImg = new Regex(@"<img\b[^<>]*?\bsrc[\s\t\r\n]*=[\s\t\r\n]*[""']?[\s\t\r\n]*(?<imgUrl>[^\s\t\r\n""'<>]*)[^<>]*?/?[\s\t\r\n]*>", RegexOptions.IgnoreCase);

            //新建一个matches的MatchCollection对象 保存 匹配对象个数(img标签)

            MatchCollection matches = regImg.Matches(htmlText);

            int i = 0;

            string[] sUrlList = new string[matches.Count];

            //遍历所有的img标签对象

            foreach (Match match in matches)

            {

                //获取所有Img的路径src,并保存到数组中

                sUrlList[i++] = match.Groups["imgUrl"].Value;

            }

            return sUrlList;

        }