《C#高级编程》读书笔记（十八）：网络

1，网络

  在网络环境下，我们最感兴趣的两个命名空间是 System.Net 和 System.Net.Sockets。 System.Net 名称空间通常与较高层的操作有关，例如下载和上传文件，使用 HTTP 和其他协议进行 Web 请求；而 System.Net.Sockets 名称空间包含的类通常与较低层的操作有关。如果要直接使用套接字或 TCP/IP 之类的协议，这个名称空间中的类就非常有用。

2，HttpClient类

  HttpClient 类用于发送 HTTP 请求，接收请求的响应。它在 System.Net.Http 名称空间中。

        static void Main(string[] args)
        {
            Console.WriteLine("In main before call to GetData!");
            GetData();
            Console.WriteLine("Back in main after call to GetData!");
            Console.ReadKey();
        }

        private static async void GetData()
        {
            HttpClient httpClient = new HttpClient();
            HttpResponseMessage response = null;
            response = await httpClient.GetAsync(
                "http://services.odata.org/northwind/northwind.svc/Regions");
            if (response.IsSuccessStatusCode)
            {
                Console.WriteLine("Response Status Code:"
                    +response.StatusCode
                    +" " + response.ReasonPhrase);
                string responseBodyAsText = response
                    .Content
                    .ReadAsStringAsync()
                    .Result;
                Console.WriteLine("Received payload of "
                    +responseBodyAsText.Length
                    + " characters");
            }
        }                                                                       

3，把输出结果显示为HTML页面

 用WebBrowser控件实现：

using System.Windows.Forms;

namespace Browser
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == (char) 13)
            {
                webBrowser1.Navigate(textBox1.Text);
            }
        }
    }
}

4，实用工具类

  1）URI

  Uri和UriBuilder 是 System 名称空间中的两个类，他们都用于表示 URI。UriBuilder 类允许把给定的字符串当做URI的组成部分，从而构建一个URI;而 Uri 类允许分析、组合和比较URI。

        static void Main(string[] args)
        {
            Uri MSPage = new Uri("http://www.Microsoft.com/SomeFolder/SomeFile.htm?Order=true");
            Console.WriteLine(MSPage.Query);
            Console.WriteLine(MSPage.AbsolutePath);
            Console.WriteLine(MSPage.Scheme);
            Console.WriteLine(MSPage.Port);
            Console.WriteLine(MSPage.Host);
            Console.WriteLine(MSPage.IsDefaultPort);
            Console.ReadKey();                                                                                      
        }

UriBuilder MSPage = new UriBuilder("http","www.microsoft",80,"SomeFolder/SomeFile.htm");

  2）IP 地址和 DNS 名称

            IPAddress ipAddress = IPAddress.Parse("234.56.78.9");
            string ipString = ipAddress.ToString();
            Console.WriteLine(ipString);

            Console.ReadKey();

            IPHostEntry wroxHost = Dns.GetHostEntry("www.wrox.com");
            IPHostEntry wroxHostCopy = Dns.GetHostEntry("208.215.179.178");

5，较低层的协议

  Tcp类：TcpSend和TcpReceive示例

using System;
using System.IO;
using System.Net.Sockets;
using System.Windows.Forms;

namespace TcpSend
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            TcpClient tcpClient = new TcpClient(textBox1.Text,int.Parse(textBox2.Text));
            NetworkStream ns = tcpClient.GetStream();
            FileStream fs = File.Open("Form1.cs", FileMode.Open);
            int data = fs.ReadByte();

            while (data != -1)
            {
                ns.WriteByte((byte)data);
                data = fs.ReadByte();
            }

            fs.Close();
            ns.Close();
            tcpClient.Close();
        }
    }
}

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Windows.Forms;

namespace TcpReceive
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            Thread thread = new Thread(new ThreadStart(Listen));
            thread.Start();
        }

        public void Listen()
        {
            IPAddress localAddr = IPAddress.Parse("127.0.0.1");
            Int32 port = 2112;
            TcpListener tcpListener = new TcpListener(localAddr,port);
            tcpListener.Start();

            TcpClient tcpClient = tcpListener.AcceptTcpClient();

            NetworkStream ns = tcpClient.GetStream();
            StreamReader sr = new StreamReader(ns);
            string result = sr.ReadToEnd();
            Invoke(new UpdateDisplayDelegate(UpdateDisplay), new object[] { result });
            tcpClient.Close();
            tcpListener.Stop();
        }

        public void UpdateDisplay(string text)
        {
            txtDisplay.Text = text;
        }

        protected delegate void UpdateDisplayDelegate(string text);
    }
}

  Socket类

  Socket类提供了网络编程中最高级的控制。

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Windows.Forms;

namespace TcpReceive
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            Thread thread = new Thread(new ThreadStart(Listen));
            thread.Start();
        }

        public void Listen()
        {
            Socket listener = new Socket(AddressFamily.InterNetwork,
                SocketType.Stream, 
                ProtocolType.Tcp);
            listener.Bind(new IPEndPoint(IPAddress.Any, 2112));
            listener.Listen(0);
            Socket socket = listener.Accept();
            Stream netStream = new NetworkStream(socket);
            StreamReader reader = new StreamReader(netStream);
            string result = reader.ReadToEnd();
            Invoke(new UpdateDisplayDelegate(UpdateDisplay), result);
            socket.Close();
            listener.Close();
        }

        public void UpdateDisplay(string text)
        {
            txtDisplay.Text = text;
        }

        protected delegate void UpdateDisplayDelegate(string text);
    }
}