1   public void ProcessRequest(HttpContext context)
 2         {
 3             String tmpfileName = context.Request.QueryString["FileName"];
 4 
 5             string fileName = UnicodeConvert.FromUnicode(tmpfileName); ;
 6             string filePath = AppDomain.CurrentDomain.BaseDirectory + fileName;
 7             System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
 8             if (fileInfo.Exists == true)
 9             {
10                 byte[] buffer = new byte[ChunkSize];
11 
12                 context.Response.Clear();
13 
14                 FileStream iStream = File.OpenRead(filePath);
15                 long dataLengthToRead = iStream.Length; //获取下载的文件总大小
16                 context.Response.AddHeader("Content-Disposition", "attachment;  filename=" + 
17                     fileInfo.FullName);
18 
19                 context.Response.ContentType = "application/octet-stream";
20                 context.Response.AddHeader("Content-Length", fileInfo.Length.ToString());
21 
22                 while (dataLengthToRead > 0 && context.Response.IsClientConnected)
23                 {
24                     int lengthRead = iStream.Read(buffer, 0, Convert.ToInt32(102400));//'读取的大小
25 
26                     context.Response.OutputStream.Write(buffer, 0, lengthRead);
27                     context.Response.Flush();
28                     dataLengthToRead = dataLengthToRead - lengthRead;
29                 }
30                 //context.Response.Close();
31                 context.Response.End();