.net工具类——获取html字符串中的图片路径列表

调用方法：

HashSet<string> listImg = new HashSet<string>();
 
GetListHtmlString(TemplateContent, "<img src="", listImg);
GetListHtmlString(TemplateContent, "<img title="image.png" alt="image.png" src="", listImg);

帮助方法：

        /// <summary>
        /// 获取内容的html
        /// </summary>
        /// <param name="content"></param>
        /// <param name="searchStr"></param>
        /// <returns></returns>
        public static void GetListHtmlString(string content, string searchStr, HashSet<string> listImg)
        {
            if (string.IsNullOrEmpty(content) || string.IsNullOrEmpty(searchStr))
                return;

            int thisIndex = 0;
            while (true)
            {
                int startIndex = content.IndexOf(searchStr, thisIndex);
                if (startIndex == -1)
                    break;

                startIndex += searchStr.Length;

                int endIndex = content.IndexOf(""", startIndex);
                if (endIndex == -1)
                    break;

                var listChar = content.Skip(startIndex).Take(endIndex - startIndex).ToArray();
                string str = new string(listChar);
                if (str.Contains("data:image/png;base64"))
                    continue;

                if (str.Contains("http://"))
                {
                    str = str.Replace("http://www.aaa.com/Content", "/Content");

                }
                listImg.Add(str);

                thisIndex = endIndex;
            }
            return;
        }