1         /// <summary>
 2         /// 下载文件 TransmitFile
 3         /// </summary>
 4         /// <param name="filePath"></param>
 5         public static void DownloadFile(string filePath)
 6         {
 7             string filename = HttpContext.Current.Server.MapPath(filePath);
 8             var response = HttpContext.Current.Response;
 9             response.ContentType = "application/x-zip-compressed";
10             response.AddHeader("Content-Disposition", "attachment;filename=" + Path.GetFileName(filename) );
11             response.TransmitFile(filename); 
12         }
13 
14         /// <summary>
15         /// 下载大文件
16         /// </summary>
17         /// <param name="filePath"></param>
18         public static void DownloadBigFile(string filePath)
19         {
20             filePath =  HttpContext.Current.Server.MapPath(filePath);//路径
21             string fileName = Path.GetFileName(filePath);//客户端保存的文件名
22             var response = HttpContext.Current.Response;
23             System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
24             if (fileInfo.Exists == true)
25             {
26                 const long ChunkSize = 102400;//100K 每次读取文件，只读取100K，这样可以缓解服务器的压力
27 
28                 byte[] buffer = new byte[ChunkSize];
29 
30                 response.Clear();
31                 System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);
32                 long dataLengthToRead = iStream.Length;//获取下载的文件总大小
33                 response.ContentType = "application/octet-stream";
34                 response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));
35                 while (dataLengthToRead > 0 && response.IsClientConnected)
36                 {
37                     //读取的大小 Response.OutputStream.Write(buffer, 0, lengthRead);
38                     int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));
39                     response.Flush();
40                     dataLengthToRead = dataLengthToRead - lengthRead;
41                 }
42 
43                 response.Close();
44             }
45         }
46 
47         /// <summary>
48         /// 流方式下载
49         /// </summary>
50         /// <param name="filePath"></param>
51         public static void DownloadFileStream(string filePath)
52         {
53             filePath = HttpContext.Current.Server.MapPath(filePath);//路径
54             string fileName = Path.GetFileName(filePath);//客户端保存的文件名
55             var response = HttpContext.Current.Response;
56             FileStream fs = new FileStream(filePath, FileMode.Open);
57 
58             byte[] bytes = new byte[(int)fs.Length]; fs.Read(bytes, 0, bytes.Length);
59 
60             fs.Close();
61             response.ContentType = "application/octet-stream";
62             //通知浏览器下载文件而不是打开
63             response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
64             response.BinaryWrite(bytes);
65             response.Flush();
66             response.End();
67         }
68 
69         /// <summary>
70         /// 将文本作为某文件下载
71         /// </summary>
72         /// <param name="text"></param>
73         /// <param name="fileName"></param>
74         public static void DownloadText(string text , string fileName)
75         {
76             byte[] bytes = Encoding.Default.GetBytes(text);
77             var response = HttpContext.Current.Response;
78             response.ContentType = "application/octet-stream";
79             //通知浏览器下载文件而不是打开
80             response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
81             response.BinaryWrite(bytes);
82             response.Flush();
83             response.End();
84         }