UdpClient 类

定义

public ref class UdpClient : IDisposable

public class UdpClient : IDisposable

type UdpClient = class
    interface IDisposable

Public Class UdpClient
Implements IDisposable

继承

Object

UdpClient

实现

IDisposable

示例

以下示例使用端口 11000 上的主机名www.contoso.com建立UdpClient连接。 一条小字符串消息将发送到两个单独的远程主机。 方法 Receive 会阻止执行，直到收到消息。 IPEndPoint使用传递给 Receive的 显示响应主机的标识。

// With this constructor the local port number is arbitrarily assigned.
UdpClient^ udpClient = gcnew UdpClient;
try
{
   udpClient->Connect( "host.contoso.com", 11000 );

   // Send message to the host to which you have connected.
   array<Byte>^sendBytes = Encoding::ASCII->GetBytes( "Is anybody there?" );
   udpClient->Send( sendBytes, sendBytes->Length );

   // Send message to a different host using optional hostname and port parameters.
   UdpClient^ udpClientB = gcnew UdpClient;
   udpClientB->Send( sendBytes, sendBytes->Length, "AlternateHostMachineName", 11000 );

   //IPEndPoint object will allow us to read datagrams sent from any source.
   IPEndPoint^ RemoteIpEndPoint = gcnew IPEndPoint( IPAddress::Any,0 );

   // Block until a message returns on this socket from a remote host.
   array<Byte>^receiveBytes = udpClient->Receive( RemoteIpEndPoint );
   String^ returnData = Encoding::ASCII->GetString( receiveBytes );

   // Use the IPEndPoint object to determine which of these two hosts responded.
   Console::WriteLine( String::Concat( "This is the message you received ", returnData->ToString() ) );
   Console::WriteLine( String::Concat( "This message was sent from ", RemoteIpEndPoint->Address->ToString(), " on their port number ", RemoteIpEndPoint->Port.ToString() ) );
   udpClient->Close();
   udpClientB->Close();
}
catch ( Exception^ e ) 
{
   Console::WriteLine( e->ToString() );
}

// This constructor arbitrarily assigns the local port number.
UdpClient udpClient = new UdpClient(11000);
    try{
         udpClient.Connect("www.contoso.com", 11000);

         // Sends a message to the host to which you have connected.
         Byte[] sendBytes = Encoding.ASCII.GetBytes("Is anybody there?");

         udpClient.Send(sendBytes, sendBytes.Length);

         // Sends a message to a different host using optional hostname and port parameters.
         UdpClient udpClientB = new UdpClient();
         udpClientB.Send(sendBytes, sendBytes.Length, "AlternateHostMachineName", 11000);

         //IPEndPoint object will allow us to read datagrams sent from any source.
         IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);

         // Blocks until a message returns on this socket from a remote host.
         Byte[] receiveBytes = udpClient.Receive(ref RemoteIpEndPoint);
         string returnData = Encoding.ASCII.GetString(receiveBytes);

         // Uses the IPEndPoint object to determine which of these two hosts responded.
         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();
          udpClientB.Close();
          }
       catch (Exception e ) {
                  Console.WriteLine(e.ToString());
        }

     ' This constructor arbitrarily assigns the local port number.
     Dim udpClient As New UdpClient(11000)
     Try
        udpClient.Connect("www.contoso.com", 11000)
        
        ' Sends a message to the host to which you have connected.
        Dim sendBytes As [Byte]() = Encoding.ASCII.GetBytes("Is anybody there?")
        
        udpClient.Send(sendBytes, sendBytes.Length)
        
        ' Sends message to a different host using optional hostname and port parameters.
        Dim udpClientB As New UdpClient()
        udpClientB.Send(sendBytes, sendBytes.Length, "AlternateHostMachineName", 11000)
        
        ' IPEndPoint object will allow us to read datagrams sent from any source.
        Dim RemoteIpEndPoint As New IPEndPoint(IPAddress.Any, 0)
        
        ' UdpClient.Receive blocks until a message is received from a remote host.
        Dim receiveBytes As [Byte]() = udpClient.Receive(RemoteIpEndPoint)
        Dim returnData As String = Encoding.ASCII.GetString(receiveBytes)
        
        ' Which one of these two hosts responded?
        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()
        udpClientB.Close()

     Catch e As Exception
        Console.WriteLine(e.ToString())
     End Try
  End Sub

注解

类 UdpClient 提供在阻止同步模式下发送和接收无连接 UDP 数据报的简单方法。 由于 UDP 是无连接传输协议，因此无需在发送和接收数据之前建立远程主机连接。 但是，可以通过以下两种方式之一来选择建立默认远程主机：

• 使用远程主机名和端口号作为参数Create 类的UdpClient实例。

• Create 类的UdpClient实例，然后调用 Connect 方法。

可以使用 中 UdpClient 提供的任何发送方法将数据发送到远程设备。 Receive使用 方法从远程主机接收数据。

UdpClient 方法还允许发送和接收多播数据报。 JoinMulticastGroup使用 方法将 订阅UdpClient到多播组。 DropMulticastGroup使用 方法从多播组取消订阅 UdpClient 。

构造函数

属性

方法

显式接口实现

适用于

另请参阅

• TcpClient
• TCP-UDP