asp.net response.ContentType 下载文件的四种方法

原址：http://www.cnblogs.com/xtgyiq/archive/2009/07/06/1517415.html

protected void Button1_Click(object sender, EventArgs e)
    {

 1 protected void Button1_Click(object sender, EventArgs e)
 2    {
 3        //TransmitFile实现下载
 4
 5        /*
 6         微软为Response对象提供了一个新的方法TransmitFile来解决使用Response.BinaryWrite
 7         下载超过400mb的文件时导致Aspnet_wp.exe进程回收而无法成功下载的问题。
 8         代码如下：
 9        */
10
11        Response.ContentType = "application/x-zip-compressed";
12        Response.AddHeader("Content-Disposition", "attachment;filename=keji.rar");
13        string filename = Server.MapPath("keji.rar");
14        Response.TransmitFile(filename);
15        Response.Write(""javascript\" type=\"text/javascript\">");
16        Response.Write("alert(\"下载成功\");");
17        Response.Write("window.location.href=\"C_SC.aspx\";");
18        Response.Write("");
19
20    }
21    protected void Button2_Click(object sender, EventArgs e)
22    {
23
24        //WriteFile实现下载
25        string fileName = "ceshi.rar";//客户端保存的文件名
26        string filePath = Server.MapPath("keji.rar");//路径
27
28        FileInfo fileInfo = new FileInfo(filePath);
29        Response.Clear();
30        Response.ClearContent();
31        Response.ClearHeaders();
32        Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
33        Response.AddHeader("Content-Length", fileInfo.Length.ToString());
34        Response.AddHeader("Content-Transfer-Encoding", "binary");
35        Response.ContentType = "application/octet-stream";
36        Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");
37        Response.WriteFile(fileInfo.FullName);
38        Response.Flush();
39        Response.End();
40
41    }
42    protected void Button3_Click(object sender, EventArgs e)
43    {
44        //WriteFile分块下载
45
46        string fileName = "GhostXP.iso";//客户端保存的文件名
47        string filePath = Server.MapPath("GhostXP7.7.iso");//路径
48
49         System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
50
51        if (fileInfo.Exists == true)
52         {
53            const long ChunkSize = 409600;//100K 每次读取文件，只读取100Ｋ，这样可以缓解服务器的压力
54            byte[] buffer = new byte[ChunkSize];
55
56             Response.Clear();
57             System.IO.FileStream iStream = System.IO.File.OpenRead(filePath);
58            long dataLengthToRead = iStream.Length;//获取下载的文件总大小
59             Response.ContentType = "application/octet-stream";
60             Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName));
61            while (dataLengthToRead > 0 && Response.IsClientConnected)
62             {
63                int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(ChunkSize));//读取的大小
64                 Response.OutputStream.Write(buffer, 0, lengthRead);
65                 Response.Flush();
66                 dataLengthToRead = dataLengthToRead - lengthRead;
67             }
68             Response.Close();
69         }
70     }
71
72    //字符流方式下载文件
73    protected void Button4_Click(object sender, EventArgs e)
74    {
75        string fileName = "ce2.rar";//客户端保存的文件名
76        string filePath = Server.MapPath("keji.rar");//路径
77
78        //以字符流的形式下载文件
79        FileStream fs = new FileStream(filePath, FileMode.Open);
80        byte[] bytes = new byte[(int)fs.Length];
81        fs.Read(bytes, 0, bytes.Length);
82        fs.Close();
83        Response.ContentType = "application/octet-stream";
84        //通知浏览器下载文件而不是打开
85        Response.AddHeader("Content-Disposition", "attachment;   filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
86        Response.BinaryWrite(bytes);
87        Response.Flush();
88        Response.End();
89
90    }