示例C#利用UdpClient发送广播消息

首先写个接受消息的客户端。这里偷了点懒，new UdpClient(11000)就是用Udp方式侦听11000端口，侦听任何发送到11000端口的消息都会接收到。

 

代码

   
     

    
      
    
      UdpClient udpClient 
    
      =
    
       
    
      new
    
       UdpClient(
    
      11000
    
      ); 

    
      try
    
       
{ 
 IPEndPoint RemoteIpEndPoint 
    
      =
    
       
    
      new
    
       IPEndPoint(IPAddress.Any, 
    
      0
    
      ); 
 Byte[] receiveBytes 
    
      =
    
       udpClient.Receive(
    
      ref
    
       RemoteIpEndPoint); 
 
    
      string
    
       returnData 
    
      =
    
       Encoding.ASCII.GetString(receiveBytes); 

 Console.WriteLine(
    
      "
    
      This is the message you received 
    
      "
    
       
    
      +
    
       
 returnData.ToString()); 
 Console.WriteLine(
    
      "
    
      This message was sent from 
    
      "
    
       
    
      +
    
       
 RemoteIpEndPoint.Address.ToString() 
    
      +
    
       
 
    
      "
    
       on their port number 
    
      "
    
       
    
      +
    
       
 RemoteIpEndPoint.Port.ToString()); 

 udpClient.Close(); 
} 

    
      catch
    
       (Exception e) 
{ 
 Console.WriteLine(e.ToString()); 
}

   
     

 

 

 

然后写个发Udp的服务器

 

代码

   
     

    
      
    
      UdpClient udpClient 
    
      =
    
       
    
      new
    
       UdpClient(
    
      11001
    
      ); 

    
      try
    
       
{ 
 udpClient.Connect(IPAddress.Parse(
    
      "
    
      192.168.0.255
    
      "
    
      ), 
    
      11000
    
      ); 
 Byte[] sendBytes 
    
      =
    
       Encoding.ASCII.GetBytes(
    
      "
    
      Is anybody thereA?
    
      "
    
      ); 

 udpClient.Send(sendBytes, sendBytes.Length); 

 udpClient.Close();

} 

    
      catch
    
       (Exception e) 
{ 
 Console.WriteLine(e.ToString()); 
}

   
     

 

 

 

其中192.168.0.255是你的内网广播地址，11000是客户端的端口。

广播地址是通过你的子网掩码获得的例如你的网关是192.168.0.1，掩码是255.255.255.0，那么你的广播地址就是192.168.0.255.