C#簡單的UDP通信例子加代碼

1，UDP客戶端

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Net;

namespace WindowsFormsApplication14
{
    public partial class Form1 : Form
    {
        UdpClient udpClient;
        IPEndPoint ipEndPoint;

        public Form1()
        {
            InitializeComponent();
            udpClient = new UdpClient(12345);
            ipEndPoint = new IPEndPoint(IPAddress.Parse("192.168.1.241"), 60000);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            //byte[] mybyte = Encoding.Default.GetBytes("nihao");
            
            byte[] mybyte = new byte[4];
            mybyte[0] = 0x12;
            mybyte[1] = 0x00;
            mybyte[2] = 0x34;
            mybyte[3] = 0x00;

            
            udpClient.Send(mybyte, mybyte.Length,ipEndPoint);
        }
    }
}

2，UDP服務器

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Net;

namespace WindowsFormsApplication15
{
    public partial class Form1 : Form
    {
        UdpClient udpServer;
        IPEndPoint ipEndPoint;

        public Form1()
        {
            InitializeComponent();
            udpServer = new UdpClient(23456);
            ipEndPoint = new IPEndPoint(new IPAddress(0), 0);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            
            byte[] data = udpServer.Receive(ref ipEndPoint);
            MessageBox.Show ( Encoding.Default.GetString(data));
        }
    }
}

3，讀接收緩沖區當前數據個數

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Net;

namespace WindowsFormsApplication15
{
    public partial class Form1 : Form
    {
        UdpClient udpServer;
        IPEndPoint ipEndPoint;

        public Form1()
        {
            InitializeComponent();
            udpServer = new UdpClient(23456);
            ipEndPoint = new IPEndPoint(new IPAddress(0), 0);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            byte[] outValue =  BitConverter.GetBytes(0);
            udpServer.Client.IOControl(IOControlCode.DataToRead, null, outValue);


            MessageBox.Show((BitConverter.ToInt32(outValue,0)).ToString());//發送數據發現此時數據增長，但不會超過8K
            //MessageBox.Show((BitConverter.ToString(outValue)).ToString());

        }
    }
}

4，上例有點復雜，看下面的例子，這個例子還可以說明如何設置非阻塞Socket通訊

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Net;

namespace WindowsFormsApplication15
{
    public partial class Form1 : Form
    {
        UdpClient udpServer;
        IPEndPoint ipEndPoint;

        public Form1()
        {
            InitializeComponent();
            udpServer = new UdpClient(23456);
            ipEndPoint = new IPEndPoint(new IPAddress(0), 0);
            udpServer.Client.Blocking = false; //設置為非阻塞模式
        }

        private void button1_Click(object sender, EventArgs e)
        {