1. 上传文件 FileStream fsRead = new FileStream(fileurl, FileMode.Open); int fsLen = (int)fsRead.Length; byte[] heByte = new byte[fsLen]; fsRead.Read(heByte, 0, heByte.Length); long length = fsRead.Length; string filename = fsRead.Name.Substring(fsRead.Name.LastIndexOf("\") + 1); fsRead.Close(); try { HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http:.../cunnar/upload?cId=" + cId + "&fileId=" + contractid + "&fileLength=" + length + "&fileName=" + filename); request.CookieContainer = new CookieContainer(); request.Method = "POST"; request.ContentType = "application/octet-stream"; request.ContentLength = heByte.Length; request.GetRequestStream().Write(heByte, 0, heByte.Length); HttpWebResponse response = (HttpWebResponse)request.GetResponse(); Stream stream = response.GetResponseStream(); StreamReader sr = new StreamReader(stream); string result = sr.ReadToEnd(); jsonCode = Newtonsoft.Json.JsonConvert.DeserializeObject<ReturnJsonCode>(result); } catch (Exception ex) { jsonCode.code = -1; jsonCode.msg = "上传失败!"; } 2. 下载文件(直接打开pdf文件的数据流) public Stream DownloadFile(string cId, string cFileId) { ReturnJsonCode jsonCode=new ReturnJsonCode(); try { string url = "http://.../cunnar/download?cId=" + cId + "&cFileId=" + cFileId; HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.ContentType = "application/pdf"; HttpWebResponse response = (HttpWebResponse)request.GetResponse(); Stream stream = response.GetResponseStream(); return stream; } catch (Exception ex) {return null; } 调用下载文件方法 Stream fs = cert.DownloadFile("4960332", "1263932"); MemoryStream ms = new MemoryStream(); fs.CopyTo(ms); Response.ClearContent(); Response.ContentType = "application/pdf"; Response.AddHeader("Content-Disposition", "inline;FileName=out.pdf"); Response.BinaryWrite(ms.ToArray());