《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);
}
}