UdpClient 类
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
提供用户数据报协议 (UDP) 网络服务。
public ref class UdpClient : IDisposablepublic class UdpClient : IDisposabletype UdpClient = class
interface IDisposablePublic Class UdpClient
Implements IDisposable- 继承
-
UdpClient
- 实现
示例
以下示例使用端口 11000 上的主机名www.contoso.com建立UdpClient连接。 小字符串消息将发送到两个单独的远程主机。 该方法 Receive 会阻止执行，直到收到消息。 IPEndPoint使用传递给Receive的主机标识会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
此类 UdpClient 提供用于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选择建立默认远程主机：
可以使用其中 UdpClient 提供的任何发送方法将数据发送到远程设备。 使用此方法 Receive 从远程主机接收数据。
备注
请勿使用主机名IPEndPoint或已指定默认远程主机进行调用Send。 如果这样做， UdpClient 将引发异常。
UdpClient 方法还允许发送和接收多播数据报。 使用该方法 JoinMulticastGroup 订阅 UdpClient 多播组。 使用该方法 DropMulticastGroup 取消订阅多播组的订阅 UdpClient 。
构造函数
| UdpClient() |
初始化 UdpClient 类的新实例。 |
| UdpClient(AddressFamily) |
初始化 UdpClient 类的新实例。 |
| UdpClient(Int32) |
初始化 UdpClient 类的新实例，并将它绑定到所提供的本地端口号。 |
| UdpClient(Int32, AddressFamily) |
初始化 UdpClient 类的新实例，并将它绑定到所提供的本地端口号。 |
| UdpClient(IPEndPoint) |
初始化 UdpClient 类的新实例，并将其绑定到指定的本地终结点。 |
| UdpClient(String, Int32) |
初始化 UdpClient 类的新实例，并建立默认远程主机。 |
属性
| Active |
获取或设置一个值，该值指示是否已建立默认远程主机。 |
| Available |
获取从网络接收的可读取的数据量。 |
| Client |
获取或设置基础网络 Socket。 |
| DontFragment |
获取或设置 Boolean 值，该值指定 UdpClient 是否允许将 Internet 协议 (IP) 数据报分段。 |
| EnableBroadcast | |
| ExclusiveAddressUse | |
| MulticastLoopback |
获取或设置 Boolean 值，该值指定是否将输出多播数据包传递给发送应用程序。 |
| Ttl |
获取或设置一个值，它指定由 UdpClient 发送的 Internet 协议 (IP) 数据包的生存时间 (TTL)。 |
方法
显式接口实现
| IDisposable.Dispose() |
此 API 支持产品基础结构，不能在代码中直接使用。 释放由 UdpClient 使用的所有资源。 |