C#实现下载远程图片保存到本地

     /// <summary>
        /// 执行下载并保存到本地
        /// </summary>
        /// <param name="url">图片地址</param>
        /// <param name="dtnow">保存的文件名</param>

        public void Down(string url, string dtnow)
        {
            WebRequest wreq = WebRequest.Create(url);

            HttpWebResponse wresp = (HttpWebResponse)wreq.GetResponse();
            Stream s = wresp.GetResponseStream();
            System.Drawing.Image img;
            img = System.Drawing.Image.FromStream(s);
            img.Save("E:\\" + dtnow, ImageFormat.Jpeg);
            MemoryStream ms = new MemoryStream();
            img.Save(ms, ImageFormat.Jpeg);
            img.Dispose();


        }