UdpClient.Receive(IPEndPoint) 方法

定义

命名空间:

System.Net.Sockets

程序集:

System.Net.Sockets.dll

Source:

UDPClient.cs

返回由远程主机发送的 UDP 数据报。

public:
 cli::array <System::Byte> ^ Receive(System::Net::IPEndPoint ^ % remoteEP);

public byte[] Receive (ref System.Net.IPEndPoint? remoteEP);

member this.Receive : IPEndPoint -> byte[]

Public Function Receive (ByRef remoteEP As IPEndPoint) As Byte()

参数

remoteEP

IPEndPoint

一个 IPEndPoint，它表示从其发送数据的远程主机。

返回

Byte[]

一个 Byte 类型的数组，它包含数据报数据。

例外

ObjectDisposedException

已关闭基础 Socket。

SocketException

访问套接字时出错。

示例

下面的示例演示 Receive 方法。 方法 Receive 将阻止执行，直到收到消息。 IPEndPoint使用传递给 Receive的 显示响应主机的标识。

//Creates a UdpClient for reading incoming data.
UdpClient^ receivingUdpClient = gcnew UdpClient( 11000 );

//Creates an IPEndPoint to record the IP Address and port number of the sender. 
// The IPEndPoint will allow you to read datagrams sent from any source.
IPEndPoint^ RemoteIpEndPoint = gcnew IPEndPoint( IPAddress::Any,0 );
try
{
   // Blocks until a message returns on this socket from a remote host.
   array<Byte>^receiveBytes = receivingUdpClient->Receive(  RemoteIpEndPoint );

   String^ returnData = Encoding::ASCII->GetString( receiveBytes );

   Console::WriteLine( "This is the message you received {0}", returnData );
   Console::WriteLine( "This message was sent from {0} on their port number {1}",
      RemoteIpEndPoint->Address, RemoteIpEndPoint->Port );
}
catch ( Exception^ e ) 
{
   Console::WriteLine( e->ToString() );
}

 //Creates a UdpClient for reading incoming data.
 UdpClient receivingUdpClient = new UdpClient(11000);

 //Creates an IPEndPoint to record the IP Address and port number of the sender.
// The IPEndPoint will allow you to read datagrams sent from any source.
 IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
 try{

     // Blocks until a message returns on this socket from a remote host.
     Byte[] receiveBytes = receivingUdpClient.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());
 }
 catch ( Exception e ){
     Console.WriteLine(e.ToString());
 }

   'Creates a UdpClient for reading incoming data.
   Dim receivingUdpClient As New UdpClient(11000)
   
   'Creates an IPEndPoint to record the IP address and port number of the sender. 
   ' The IPEndPoint will allow you to read datagrams sent from any source.
   Dim RemoteIpEndPoint As New IPEndPoint(IPAddress.Any, 0)
   Try
      
      ' Blocks until a message returns on this socket from a remote host.
      Dim receiveBytes As [Byte]() = receivingUdpClient.Receive(RemoteIpEndPoint)
      
      Dim returnData As String = 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()))
   Catch e As Exception
      Console.WriteLine(e.ToString())
   End Try
End Sub

注解

方法 Receive 将阻止，直到数据报从远程主机到达。 当数据可用时， Receive 方法将读取第一个排队的数据报，并将数据部分作为字节数组返回。 此方法使用remoteEPIPAddress发送方的 和 端口号填充 参数。

如果在 方法中 Connect 指定默认远程主机，该方法 Receive 将仅接受来自该主机的数据报。 将丢弃所有其他数据报。

如果收到 SocketException，请使用 SocketException.ErrorCode 获取特定的错误代码。 获取此代码后，可以参阅 Windows 套接字版本 2 API 错误代码 文档，获取错误的详细说明。

注意

如果打算接收多播数据报，请不要在调用 Connect 方法之前调用 Receive 方法。 UdpClient必须使用多播端口号创建用于接收数据报的 。

另请参阅

• Send(Byte[], Int32, IPEndPoint)
• IPEndPoint
• Connect(String, Int32)
• IPAddress