实现MSDN CSDN导航树效果ASP.Net+JavaScript的方法

使用该 URL http://localhost/WebApplicationX/WebForm1.aspx 在 Flashget 中下载

切换 暂停/开始 , 并增加下载的块数 测试!

原理参见上一篇 blog JSP/Servlet 实现版:

http://blog.csdn.net/playyuer/archive/2004/07/30/56538.aspx

利用该原理不难实现支持数据库大字段的断点续传多线程链接的下载!

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

public class WebForm1 : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{

string s = @"e:/northwind.mdb";
s = @"I://SetupRes//Sun//j2re-1_4_2_05-windows-i586-p.exe";
System.IO.Stream S = new System.IO.FileStream(s, System.IO.FileMode.Open, System.IO.FileAccess.Read,System.IO.FileShare.Read);

long p = 0;

long l = new System.IO.FileInfo(s).Length;

if (Request.Headers["Range"] != null)
{
Response.StatusCode = 206;
p = long.Parse( Request.Headers["Range"].Replace("bytes=","").Replace("-",""));
}

Response.AddHeader("Content-Length", ((long)(l - p)).ToString() );

if (p != 0)
{
//不是从最开始下载,
//响应的格式是:
//Content-Range: bytes [文件块的开始字节]-[文件的总大小 - 1]/[文件的总大小]
Response.AddHeader("Content-Range","bytes " + p.ToString() + "-" + ((long)(l - p)).ToString() + "/" + l.ToString());
}

Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=" + System.IO.Path.GetFileName(s));

S.Position = p;

int i = 1;
byte[] b = new Byte[1024];
while (i > 0)
{
i = S.Read(b, 0, b.Length);
Response.OutputStream.Write(b, 0, i);
}

S.Close();
Response.End();
}
#region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}

///