http put,delete请求

        /// <summary>
        /// PUT 方法只要IIS开启写入就可以上传文件txt/html/gif 等图片（不能asp/aspx/shtm/cer/asa/stm/
        /// 因此当网站提供IIS写入功能可以上传gif等文件然后替换原来的图片达到修改页面的目的
        /// </summary>
        /// <param name="url"></param>
        /// <param name="local"></param>
        /// <returns></returns>
        public static bool UpLoadFile(String url, String local)
        {
            try
            {
                System.Net.WebClient myWebClient = new System.Net.WebClient();
                byte[] ret = myWebClient.UploadFile(url, "DELETE", local);
                String strMessage = Encoding.ASCII.GetString(ret, 0, ret.Length);
            }
            catch (Exception exp)
            {
                throw exp;
            }
            return true;

        }
        /// <summary>
        /// DELETE 方法只要IIS开启写入就可以删除文件txt/html/gif  等图片（不能asp/aspx/shtm/cer/asa/stm/
        /// </summary>
        /// <param name="url"></param>
        /// <param name="local"></param>
        /// <returns></returns>

        public static bool DeleteFile()
        {
            try
            {
                System.Net.WebClient myWebClient = new System.Net.WebClient();

                HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://localhost/1.txt");
                request.Method = "DELETE";
                request.ContentType = "application/x-www-form-urlencoded";
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                if (response.StatusCode == HttpStatusCode.OK)
                {         // some code   
                }
            }
            catch (Exception exp)
            {
                throw exp;
            }
            return true;

        }