UDP

前面啥也没有

static void Main(string[] args)  
{  
    UdpClient client = new UdpClient(new IPEndPoint(IPAddress.Any, 0));//不指定网卡、端口发送
    client = new UdpClient(new IPEndPoint(IPAddress.Parse("1.1.1.1"), 0));//设置网卡发送
    IPEndPoint endpoint = new IPEndPoint(IPAddress.Parse("255.255.255.255"), 7788);  
    byte[] buf = Encoding.Default.GetBytes("Hello from UDP broadcast");  
    Thread t = new Thread(new ThreadStart(RecvThread));  
    t.IsBackground = true;  
    t.Start();  
    while (true)  
    {  
        client.Send(buf, buf.Length, endpoint);  
        Thread.Sleep(1000);  
    }  
}  

static void RecvThread()  
{  
    UdpClient client = new UdpClient(new IPEndPoint(IPAddress.Any, 7788));  
    IPEndPoint endpoint = new IPEndPoint(IPAddress.Any, 0);  
    while (true)  
    {  
        byte[] buf = client.Receive(ref endpoint);  
        string msg = Encoding.Default.GetString(buf);  
        Console.WriteLine(msg);  
    }  
}

/// <summary>
/// 发送UDP消息
/// </summary>
/// <param name="msg">消息内容</param>
void Send(string msg)
{
    UdpClient udpClient = new UdpClient();
    IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Broadcast, 10249);
    // IPAddress.Broadcast 就是 255.255.255.255
    byte[] buffer = Encoding.UTF8.GetBytes(msg);
    udpClient.Send(buffer, buffer.Length, ipEndPoint);
}

static void Main()
{
    UdpClient udpServer = new UdpClient(10249);
    IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Any, 10249);

    udpServer.BeginReceive(Received, udpServer);
}

/// <summary>
/// 异步接收UDP数据
/// </summary>
/// <param name="iar"></param>
void Received(IAsyncResult iar)
{
　　udpServer = iar.AsyncState as UdpClient;
　　byte[] buffer = udpServer.EndReceive(iar, ref ipEndPoint);

　　//将获取的byte[]数据转换成字符串
　　string m = Encoding.UTF8.GetString(buffer).Trim();

　　Console.WriteLine("Receive:{0}",m);

　　//继续异步接收数据
　　udpServer.BeginReceive(Received, udpServer);
}