一、概述
UDP和TCP是网络通讯常用的两个传输协议，C#一般可以通过Socket来实现UDP和TCP通讯，由于.NET框架通过UdpClient、TcpListener 、TcpClient这几个类对Socket进行了封装，使其使用更加方便， 本文就通过这几个封装过的类讲解一下相关应用。
二、UDP基本应用
与TCP通信不同，UDP通信是不分服务端和客户端的，通信双方是对等的。为了描述方便，我们把通信双方称为发送方和接收方。
发送方：
首先创建一个UDP对象：
string locateIP = "127.0.0.1"; //本机IP int locatePort = 9001; //发送端口 IPAddress locateIpAddr = IPAddress.Parse(locateIP); IPEndPoint locatePoint = new IPEndPoint(locateIpAddr, locatePort); UdpClient udpClient = new UdpClient(locatePoint);
发送数据：
string remoteIP = "127.0.0.1"; //目标机器IP int remotePort = 9002; //接收端口 IPAddress remoteIpAddr = IPAddress.Parse(remoteIP); IPEndPoint remotePoint = new IPEndPoint(remoteIpAddr, remotePort); byte[] buffer = Encoding.UTF8.GetBytes(“hello”); udpClient.Send(buffer, buffer.Length, remotePoint);
以上就完成了一个发送任务，一个较完整的发送代码如下：
public partial class FormServer : Form
{
private UdpClient udpClient = null;
private void btnConnect_Click(object sender, EventArgs e)
{
string locateIP = "127.0.0.1";
int locatePort = 9001;
IPAddress locateIpAddr = IPAddress.Parse(locateIP);
IPEndPoint locatePoint = new IPEndPoint(locateIpAddr, locatePort);
udpClient = new UdpClient(locatePoint);
this.groupWork.Enabled = true;
}
private void Send_Click(object sender, EventArgs e)
{
string text = this.txtSend.Text.Trim();
string remoteIP = "127.0.0.1";
int remotePort = 9002;
byte[] buffer = Encoding.UTF8.GetBytes(text);
if (udpClient != null)
{
IPAddress remoteIp = IPAddress.Parse(remoteIP);
IPEndPoint remotePoint = new IPEndPoint(remoteIp, remotePort);
udpClient.Send(buffer, buffer.Length, remotePoint);
}
Debug.WriteLine("Send OK");
}
}
接收端：
首先创建一个UDP对象：
string locateIP = "127.0.0.1"; int locatePort = 9002; IPAddress locateIpAddr = IPAddress.Parse(locateIP); IPEndPoint locatePoint = new IPEndPoint(locateIpAddr, locatePort); UdpClient udpClient = new UdpClient(locatePoint);
接收数据：
IPEndPoint remotePoint = new IPEndPoint(IPAddress.Parse("1.1.1.1"), 1);
var received = udpClient.Receive(ref remotePoint);
string info = Encoding.UTF8.GetString(received);
string from=$” {remotePoint.Address}:{remotePoint.Port}”;
注意两点：
1、remotePoint是获得发送方的IP信息，定义时可以输入任何合法的IP和端口信息；
2、Receive方法是阻塞方法，所以需要在新的线程内运行，程序会一直等待接收数据，当接收到一包数据时程序就返回，要持续接收数据需要重复调用Receive方法。
一个较完整的接收端代码如下：
public partial class FormClent : Form
{
private UdpClient udpClient = null;
private void btnConnect_Click(object sender, EventArgs e)
{
string locateIP = "127.0.0.1";
int locatePort = 9002;
IPAddress locateIpAddr = IPAddress.Parse(locateIP);
IPEndPoint locatePoint = new IPEndPoint(locateIpAddr, locatePort);
udpClient = new UdpClient(locatePoint);
IPEndPoint remotePoint = new IPEndPoint(IPAddress.Parse("1.1.1.1"), 1);
Task.Run(() =>
{
while (true)
{
if (udpClient<a>本文来源gao*daima.com搞@代#码&网6</a> != null)
{
var received = udpClient.Receive(ref remotePoint);
string info = Encoding.UTF8.GetString(received);
string from=$” {remotePoint.Address}:{remotePoint.Port}”;
}
}
});
}
}
三、丢包和乱序问题
搞代码网（gaodaima.com）提供的所有资源部分来自互联网，如果有侵犯您的版权或其他权益，请说明详细缘由并提供版权或权益证明然后发送到邮箱[email protected]，我们会在看到邮件的第一时间内为您处理，或直接联系QQ：872152909。本网站采用BY-NC-SA协议进行授权
转载请注明原文链接：C# 网络编程之UDP
转载请注明原文链接：C# 网络编程之UDP
