控件定义代码是:
public System.Windows.Forms.ListBox listBox1;private System.Windows.Forms.Label label1;private System.Windows.Forms.TextBox textBox1private System.Windows.Forms.Button button1;private System.Windows.Forms.Label label2;private System.Windows.Forms.TextBox textBox2;private System.Windows.Forms.Label label3;private System.Windows.Forms.TextBox textBox3;private System.Windows.Forms.Label label4;private System.Windows.Forms.TextBox textBox4;(本文来源于图老师网站,更多请访问http://m.tulaoshi.com/bianchengyuyan/)
打开Form1的代码编辑器,增加如下的命名空间:
using System.Net;//网络功能using System.IO;//流支持using System.Threading ;//线程支持
增加如下的程序变量:
public bool[] threadw; //每个线程结束标志public string[] filenamew;//每个线程接收文件的文件名public int[] filestartw;//每个线程接收文件的起始位置public int[] filesizew;//每个线程接收文件的大小public string strurl;//接受文件的URLpublic bool hb;//文件合并标志public int thread;//进程数
定义一个HttpFile类,用于管理接收线程,其代码如下:
public class HttpFile{ public Form1 formm; public int threadh;//线程代号 public string filename;//文件名 public string strUrl;//接收文件的URL public FileStream fs; public HttpWebRequest request; public System.IO.Stream ns; public byte[] nbytes;//接收缓冲区 public int nreadsize;//接收字节数 public HttpFile(Form1 form,int thread)//构造方法 { formm=form; threadh=thread; } ~HttpFile()//析构方法 { formm.Dispose (); } public void receive()//接收线程 { filename=formm.filenamew[threadh]; strUrl=formm.strurl; ns=null; nbytes= new byte[512]; nreadsize=0; formm.listBox1 .Items .Add ("线程"+threadh.ToString ()+"开始接收"); fs=new FileStream (filename,System.IO.FileMode.Create); try { request=(HttpWebRequest)HttpWebRequest.Create (strUrl); //接收的起始位置及接收的长度 request.AddRange(formm.filestartw [threadh], formm.filestartw [threadh]+formm.filesizew [threadh]); ns=request.GetResponse ().GetResponseStream ();//获得接收流 nreadsize=ns.Read (nbytes,0,512); while (nreadsize0) { fs.Write (nbytes,0,nreadsize); nreadsize=ns.Read (nbytes,0,512); formm.listBox1 .Items .Add ("线程"+threadh.ToString ()+"正在接收"); } fs.Close(); ns.Close (); } catch (Exception er) { MessageBox.Show (er.Message ); fs.Close(); } formm.listBox1 .Items.Add ("进程"+threadh.ToString ()+"接收完毕!"); formm.threadw[threadh]=true; }}
该类和Form1类处于统一命名空间,但不包含在Form1类中。下面定义开始接收按钮控件的事件响应函数:
(本文来源于图老师网站,更多请访问http://m.tulaoshi.com/bianchengyuyan/)
private void button1_Click(object sender, System.EventArgs e){ DateTime dt=DateTime.Now;//开始接收时间 textBox1.Text =dt.ToString (); strurl=textBox2.Text .Trim ().ToString (); HttpWebRequest request; long filesize=0; try { request=(HttpWebRequest)HttpWebRequest.Create (strurl); filesize=request.GetResponse ().ContentLength;//取得目标文件的长度 request.Abort (); } catch (Exception er) { MessageBox.Show (er.Message ); } // 接收线程数 thread=Convert.ToInt32 (textBox4.Text .Trim().ToString (),10); //根据线程数初始化数组 threadw=new bool [thread]; filenamew=new string [thread]; filestartw=new int [thread]; filesizew=new int[thread]; //计算每个线程应该接收文件的大小 int filethread=(int)filesize/thread;//平均分配 int filethreade=filethread+(int)filesize%thread;//剩余部分由最后一个线程完成 //为数组赋值 for (int i=0;ithread;i++) { threadw[i]=false;//每个线程状态的初始值为假 filenamew[i]=i.ToString ()+".dat";//每个线程接收文件的临时文件名 if (ithread-1) { filestartw[i]=filethread*i;//每个线程接收文件的起始点 filesizew[i]=filethread-1;//每个线程接收文件的长度 } else { filestartw[i]=filethread*i; filesizew[i]=filethreade-1; } } //定义线程数组,启动接收线程 Thread[] threadk=new Thread [thread]; HttpFile[] httpfile=new HttpFile [thread]; for (int j=0;jthread;j++) { httpfile[j]=new HttpFile(this,j); threadk[j]=new Thread(new ThreadStart (httpfile[j].receive )); threadk[j].Start (); } //启动合并各线程接收的文件线程 Thread hbth=new Thread (new ThreadStart (hbfile)); hbth.Start ();}