c# 文件下载 进度及速度

 

                                      

visual studio 2005 + winxp sp2

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using Microsoft.Win32;
using System.Runtime.InteropServices;
using System.Net;
using System.Net.Sockets;

namespace CommonLibrary
{
    public partial class Form1 : Form
    {
        private WebRequest httpRequest;
        private WebResponse httpResponse;
        private byte[] buffer;
        private Thread downloadThread;
        Stream ns;
        private string filename = @"d:\hello1.mp3";
        private FileStream fs;
        private long length;
        private long downlength=0;
        private long lastlength = 0;
        public delegate void updateData(string value); //设置委托用来更新主界面
        private int totalseconds = 0; //总用时
        private updateData UIDel; //
        public Form1()
        {
            InitializeComponent();
            buffer = new byte[4096];
           
        }

        private void button1_Click(object sender, EventArgs e)
        {
            httpRequest = WebRequest.Create(this.textBox1.Text);
            httpResponse = httpRequest.GetResponse();
            //MessageBox.Show(httpResponse.ContentLength.ToString());
            length = httpResponse.ContentLength;
            this.progressBar1.Maximum =(int) length;
            this.progressBar1.Minimum = 0;
            downloadThread = new Thread(new ThreadStart(downloadFile));
            //showThread = new Thread(new ThreadStart(show));
            fs = new FileStream(filename, FileMode.OpenOrCreate, FileAccess.Write);
            downloadThread.Start();
            this.timer1.Enabled = true;
           // showThread.Start();
        }
        private void downloadFile( )
        {
          
            ns = httpResponse.GetResponseStream();
           
            int i;
            UIDel = new updateData(updateUI);
            while ((i = ns.Read(buffer, 0, buffer.Length)) > 0)
            {
               
                downlength += i;
                string value = downlength.ToString();
                this.Invoke(UIDel, value);
                fs.Write(buffer, 0, i);
            }
            MessageBox.Show("下载完毕");
            this.timer1.Enabled = false;
            this.label3.Text = (length / (1024 * totalseconds)) + "KB/s";
        }
       /* private void show()
        {
            UIDel = new updateData(updateUI);
            int value = 0;
            while (value <= 100)
            {
                this.progressBar1.Value = value;
                value++;
            } 
        }*/
       void updateUI(string value)
        {
            this.label1.Text = value;
            this.progressBar1.Value = Int32.Parse(value);
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            this.label2.Text = ((downlength - lastlength) / 1024) + "KB/S";
            lastlength = downlength;
            totalseconds++;
        }
    }
}