C# 服务端下载文件方法

引用命名空间

using System.Net;
using System.IO;

       public string DownLoadFile(){
                string url = Request["url"];//要下载的文件url链接
                string path = "/Content/File/" + DateTime.Now.ToString("yyyyMMddhhmmss");//要下载到本地的相对路径
                
                string ext="."+url.spilt('.')[1];//获取要下载文件的后缀格式

                string downpath = Server.MapPath(path)+ext;//将相对路径转为绝对路径

                // 设置参数
                HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
                //发送请求并获取相应回应数据
                HttpWebResponse response = request.GetResponse() as HttpWebResponse;
                //直到request.GetResponse()程序才开始向目标网页发送Post请求
                Stream responseStream = response.GetResponseStream();
                //创建本地文件写入流
                Stream stream = new FileStream(downpath, FileMode.Create);
                byte[] bArr = new byte[1024];
                int size = responseStream.Read(bArr, 0, (int)bArr.Length);
                while (size > 0)
                {
                    stream.Write(bArr, 0, size);
                    size = responseStream.Read(bArr, 0, (int)bArr.Length);
                }
                stream.Close();
                responseStream.Close();
                return "succeed";
       }