保存图片

 var imgUrl = "";
                WebRequest imgRequest = WebRequest.Create(imgUrl);
                HttpWebResponse res;
                res = (HttpWebResponse)imgRequest.GetResponse();
                if (res.StatusCode.ToString() == "OK")
                {
                    Image downImage = Image.FromStream(imgRequest.GetResponse().GetResponseStream());
                    string dertory = Directory.GetCurrentDirectory();
                    dertory = dertory.Replace("\\bin\\Debug", "\\ToolFile\\RucEduImg\\");
                    string fileName = string.Format("{0}.jpg", id);
                    if (!Directory.Exists(dertory))
                    {
                        Directory.CreateDirectory(dertory);
                    }
                    downImage.Save(dertory + fileName);
                    downImage.Dispose();
                    Console.WriteLine(fileName);
                }