UDP通讯
Send Receive方式
概述
为了和某一个远程主机通讯，在创建套接字后，使用Connect方法先和远程主机建立连接，然后直接用Send方法和Receive方法发送和接收数据。
发送端示例
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace SendExamples
{
/// <summary>
/// 发送数据
/// </summary>
class Program
{
static void Main(string[] args)
{
string HostIP = System.Configuration.ConfigurationManager.AppSettings["HostIP"];
int Port = Convert.ToInt32(System.Configuration.ConfigurationManager.AppSettings["Port"]);
byte[] bytes = new byte[32768];
string str = string.Empty;
Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
//定义远程终端IP地址和端口（实际使用时应为远程主机IP地址），为发送数据做准备
IPEndPoint remote = new IPEndPoint(IPAddress.Parse(HostIP), Port);
//建立与远程主机的连接
socket.Connect(remote);
while (true)
{
Console.Write("输入发送的信息（bye退出)：");
str = Console.ReadLine();
//字符串转换为字节数组
bytes = System.Text.Encoding.Unicode.GetBytes(str);
//向远程终端发送信息
socket.Send(bytes);
if (str == "bye") break;
}
socket.Close();
}
}
}
接收端示例
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace SendExamples
{
/// <summary>
/// 接收数据
/// </summary>
class Program
{
static void Main(string[] args)
{
int Port = Convert.ToInt32(System.Configuration.ConfigurationManager.AppSettings["Port"]);
int length;
byte[] bytes = new byte[32768];
string str = string.Empty;
Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
//参数1指定本机IP地址（此处指所有可用的IP地址），参数2指定接收用的端口
IPEndPoint myHost = new IPEndPoint(IPAddress.Any, Port);
//将本机IP地址和端口与套接字绑定，为接收做准备
socket.Bind(myHost);
while (true)
{
Console.WriteLine("等待接收...");
//从本地绑定的IP地址和端口接收远程终端的数据，返回接收的字节数
length = socket.Receive(bytes);
//字节数组转换为字符串
str = System.Text.Encoding.Unicode.GetString(bytes, 0, length);
if (str == "bye") break;
Console.WriteLine("接收到信息：{0}", str);
}
socket.Close();
}
}
}
SendTo ReceiveFrom方式
概述
SendTo和ReceiveFrom方法传送数据时，需要在参数中指定远程主机，这种方法适用于向多个远程主机发送数据的场合。比如动态生成远程主机的IP地址，达到向不同主机发送相同数据的目的。
发送端示例
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace SendToExamples
{
/// <summary>
/// 发送数据
/// </summary>
class Program
{
static void Main(string[] args)
{
string HostIP = System.Configuration.ConfigurationManager.AppSettings["HostIP"];
int Port = Convert.ToInt32(System.Configuration.ConfigurationManager.AppSettings["Port"]);
string str = string.Empty;
byte[] bytes = new byte[32768];
Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
//定义远程IP地址和端口（实际使用时就为远程主机IP地址，为发送数据做准备
IPEndPoint remote = new IPEndPoint(IPAddress.Parse(HostIP), Port);
//从IPEndPoint得到EndPoint类型
EndPoint remoteHost = (EndPoint)remote;
while (true)
{
Console.Write("输入发送的信息：（bye退出）");
str = Console.ReadLine();
bytes = System.Text.Encoding.Unicode.GetBytes(str);
socket.SendTo(bytes, remoteHost);
if (str == "bye") break;
}
socket.Close();
}
}
}
接收端示例
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace ReceiveFromExamples
{
/// <summary>
/// 接收数据
/// </summary>
class Program
{
static void Main(string[] args)
{
int Port = Convert.ToInt32(System.Configuration.ConfigurationManager.AppSettings["Port"]);
string str = string.Empty;
int length;
byte[] bytes = new byte[32768];
Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
//参数1指定本机IP地址（此处指所有可用的IP地址），参数2指定接收用的端口
IPEndPoint myHost = new IPEndPoint(IPAddress.Any, Port);
//将本机IP地址和端口与套接字绑定，为接收做准备
socket.Bind(myHost);
//从IPEndPoint得到EndPoint类型
EndPoint remoteHost = (EndPoint)myHost;
while (true)
{
Console.WriteLine("等待接收...");
//从本地绑定的IP地址和端口接收远程终端的数据，返回接收的字节数
length = socket.ReceiveFrom(bytes, ref remoteHost);
//字节数组转换为字符串
str = System.Text.Encoding.Unicode.GetString(bytes, 0, length);
if (str == "bye") break;
Console.WriteLine("接收到信息：{0}", str);
}
socket.Close();
}
}
}
