1 // 输出硬盘文件,提供下载 支持大文件、续传、速度限制、资源占用小
2 // 输入参数 _Request: Page.Request对象, _Response: Page.Response对象, _fileName: 下载文件名, _fullPath: 带文件名下载路径, _speed 每秒允许下载的字节数
3 // 返回是否成功
4 public static bool ResponseFile(HttpRequest _Request,HttpResponse _Response,string _fileName,string _fullPath, long _speed)
5 {
6 try
7 {
8 FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
9 BinaryReader br = new BinaryReader(myFile);
10 try
11 {
12 _Response.AddHeader("Accept-Ranges", "bytes");
13 _Response.Buffer = false;
14 long fileLength = myFile.Length;
15 long startBytes = 0;
16
17 int pack = 10240; //10K bytes
18 //int sleep = 200; //每秒5次 即5*10K bytes每秒
19 int sleep = (int)Math.Floor(1000 * pack / _speed) + 1;
20 if (_Request.Headers["Range"] != null)
21 {
22 _Response.StatusCode = 206;
23 string[] range = _Request.Headers["Range"].Split(new char[] {'=', '-'});
24 startBytes = Convert.ToInt64(range[1]);
25 }
26 _Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
27 if (startBytes != 0)
28 {
29 _Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength-1, fileLength));
30 }
31 _Response.AddHeader("Connection", "Keep-Alive");
32 _Response.ContentType = "application/octet-stream";
33 _Response.AddHeader("Content-Disposition","attachment;filename=" + HttpUtility.UrlEncode(_fileName,System.Text.Encoding.UTF8) );
34
35 br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
36 int maxCount = (int) Math.Floor((fileLength - startBytes) / pack) + 1;
37 for (int i = 0; i < maxCount; i++)
38 {
39 if (_Response.IsClientConnected)
40 {
41 _Response.BinaryWrite(br.ReadBytes(pack));
42 Thread.Sleep(sleep);
43 }
44 else
45 {
46 i=maxCount;
47 }
48 }
49 }
50 catch
51 {
52 return false;
53 }
54 finally
55 {
56 br.Close();
57 myFile.Close();
58 }
59 }
60 catch
61 {
62 return false;
63 }
64 return true;
65 }
66
67
68 //调用例
69
70 Page.Response.Clear();
71
72 bool success = ResponseFile(Page.Request, Page.Response, "filename", @"C:\download.date", 1024000);
73
74 if(!success)
75 Response.Write("下载文件出错!");
76
77 Page.Response.End();
78
79
2 // 输入参数 _Request: Page.Request对象, _Response: Page.Response对象, _fileName: 下载文件名, _fullPath: 带文件名下载路径, _speed 每秒允许下载的字节数
3 // 返回是否成功
4 public static bool ResponseFile(HttpRequest _Request,HttpResponse _Response,string _fileName,string _fullPath, long _speed)
5 {
6 try
7 {
8 FileStream myFile = new FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
9 BinaryReader br = new BinaryReader(myFile);
10 try
11 {
12 _Response.AddHeader("Accept-Ranges", "bytes");
13 _Response.Buffer = false;
14 long fileLength = myFile.Length;
15 long startBytes = 0;
16
17 int pack = 10240; //10K bytes
18 //int sleep = 200; //每秒5次 即5*10K bytes每秒
19 int sleep = (int)Math.Floor(1000 * pack / _speed) + 1;
20 if (_Request.Headers["Range"] != null)
21 {
22 _Response.StatusCode = 206;
23 string[] range = _Request.Headers["Range"].Split(new char[] {'=', '-'});
24 startBytes = Convert.ToInt64(range[1]);
25 }
26 _Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
27 if (startBytes != 0)
28 {
29 _Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength-1, fileLength));
30 }
31 _Response.AddHeader("Connection", "Keep-Alive");
32 _Response.ContentType = "application/octet-stream";
33 _Response.AddHeader("Content-Disposition","attachment;filename=" + HttpUtility.UrlEncode(_fileName,System.Text.Encoding.UTF8) );
34
35 br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
36 int maxCount = (int) Math.Floor((fileLength - startBytes) / pack) + 1;
37 for (int i = 0; i < maxCount; i++)
38 {
39 if (_Response.IsClientConnected)
40 {
41 _Response.BinaryWrite(br.ReadBytes(pack));
42 Thread.Sleep(sleep);
43 }
44 else
45 {
46 i=maxCount;
47 }
48 }
49 }
50 catch
51 {
52 return false;
53 }
54 finally
55 {
56 br.Close();
57 myFile.Close();
58 }
59 }
60 catch
61 {
62 return false;
63 }
64 return true;
65 }
66
67
68 //调用例
69
70 Page.Response.Clear();
71
72 bool success = ResponseFile(Page.Request, Page.Response, "filename", @"C:\download.date", 1024000);
73
74 if(!success)
75 Response.Write("下载文件出错!");
76
77 Page.Response.End();
78
79