asp.net心得之实现下载功能

闲话不扯，直接上码，至于下载的方式，可以直接决定，按钮、链接等等都是可行的，后端代码，如果你有心，也可以做成类文件。

 

<asp:Button ID="btnDownLoad" runat="server" Text="下载"  onclick="btnDownLoad_Click" />

 

 1 using System;
 2 using System.IO;
 3 using System.Web;
 4 
 5 public partial class UserControls_Default : System.Web.UI.Page
 6 {
 7     protected void Page_Load(object sender, EventArgs e)
 8     {
 9 
10     }
11     public void DownLoadFile(string fileName, byte[] bytes)
12     {
13         HttpResponse Response = System.Web.HttpContext.Current.Response;
14         HttpRequest Request = System.Web.HttpContext.Current.Request;
15         try
16         {
17             Response.Clear();
18             Response.ClearHeaders();
19             Response.Expires = -1;
20             Response.AddHeader("Accept-Ranges", "bytes");
21             Response.Buffer = false;
22             long startBytes = 0;
23             if (Request.Headers["Range"] != null)
24             {
25                 Response.StatusCode = 206;
26                 string[] range = Request.Headers["Range"].Split(new char[] { '=', '-' });
27                 startBytes = Convert.ToInt64(range[1]);
28             }
29             Response.AddHeader("Content-Length", (bytes.Length - startBytes).ToString());
30             if (startBytes != 0)
31             {
32                 Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, bytes.Length - 1, bytes.Length));
33             }
34             Response.AddHeader("Connection", "Keep-Alive");
35             Response.ContentType = "application/octet-stream";
36             Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
37             Response.BinaryWrite(bytes);
38             Response.Flush();
39             //Response.End();
40             System.Web.HttpContext.Current.ApplicationInstance.CompleteRequest();
41 
42         }
43         catch
44         {
45             Response.Close();
46         }
47         finally
48         {
49             Response.Close();
50         }
51     }
52 
53     /// <summary>
54 /// 下载按钮操作
55 /// </summary>
56 /// <param name="sender"></param>
57 /// <param name="e"></param>
58     protected void btnDownLoad_Click(object sender, EventArgs e)
59     {
60         string fileName = "ExampleExcel.xls";//客户端保存的文件名
61         string filePath = Server.MapPath("../DownLoad/Example.xls");//路径以字符流的形式下载文件
62         FileStream fs = new FileStream(filePath, FileMode.Open);
63         byte[] bytes = new byte[(int)fs.Length];
64         fs.Read(bytes, 0, bytes.Length);
65         fs.Close();
66         DownLoadFile(fileName, bytes);
67     }
68 }

 

posted on 2012-03-10 11:15  zhangtao1212  阅读(219)  评论(0)  编辑  收藏  举报

导航