TcpListener 类
从 TCP 网络客户端侦听连接。
**命名空间:**System.Net.Sockets
**程序集:**System（在 system.dll 中）
语法
声明
Public Class TcpListener
用法
Dim instance As TcpListener
public class TcpListener
public ref class TcpListener
public class TcpListener
public class TcpListener
备注
TcpListener 类提供一些简单方法，用于在阻止同步模式下侦听和接受传入连接请求。可使用 TcpClient 或 Socket 来连接 TcpListener。可使用 IPEndPoint、本地 IP 地址及端口号或者仅使用端口号，来创建 TcpListener。可以将本地 IP 地址指定为 Any，将本地端口号指定为 0（如果希望基础服务提供程序为您分配这些值）。如果您选择这样做，可在连接套接字后使用 LocalEndpoint 属性来标识已指定的信息。
Start 方法用来开始侦听传入的连接请求。Start 将对传入连接进行排队，直至您调用 Stop 方法或它已经完成 MaxConnections 排队为止。可使用 AcceptSocket 或 AcceptTcpClient 从传入连接请求队列提取连接。这两种方法将阻止。如果要避免阻止，可首先使用 Pending 方法来确定队列中是否有可用的连接请求。
调用 Stop 方法来关闭 TcpListener。
提示
Stop 方法不会关闭任何已接受的连接。需要用户负责分别关闭这些连接。
示例
下面的代码示例创建 TcpListener。
Imports System
Imports System.IO
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports Microsoft.VisualBasic
Class MyTcpListener
Public Shared Sub Main()
Dim server As TcpListener
server=nothing
Try
' Set the TcpListener on port 13000.
Dim port As Int32 = 13000
Dim localAddr As IPAddress = IPAddress.Parse("127.0.0.1")
server = New TcpListener(localAddr, port)
' Start listening for client requests.
server.Start()
' Buffer for reading data
Dim bytes(1024) As Byte
Dim data As String = Nothing
' Enter the listening loop.
While True
Console.Write("Waiting for a connection... ")
' Perform a blocking call to accept requests.
' You could also user server.AcceptSocket() here.
Dim client As TcpClient = server.AcceptTcpClient()
Console.WriteLine("Connected!")
data = Nothing
' Get a stream object for reading and writing
Dim stream As NetworkStream = client.GetStream()
Dim i As Int32
' Loop to receive all the data sent by the client.
i = stream.Read(bytes, 0, bytes.Length)
While (i <> 0)
' Translate data bytes to a ASCII string.
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i)
Console.WriteLine("Received: {0}", data)
' Process the data sent by the client.
data = data.ToUpper()
Dim msg As Byte() = System.Text.Encoding.ASCII.GetBytes(data)
' Send back a response.
stream.Write(msg, 0, msg.Length)
Console.WriteLine("Sent: {0}", data)
i = stream.Read(bytes, 0, bytes.Length)
End While
' Shutdown and end connection
client.Close()
End While
Catch e As SocketException
Console.WriteLine("SocketException: {0}", e)
Finally
server.Stop()
End Try
Console.WriteLine(ControlChars.Cr + "Hit enter to continue....")
Console.Read()
End Sub 'Main
End Class 'MyTcpListener
using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
class MyTcpListener
{
public static void Main()
{
TcpListener server=null;
try
{
// Set the TcpListener on port 13000.
Int32 port = 13000;
IPAddress localAddr = IPAddress.Parse("127.0.0.1");
// TcpListener server = new TcpListener(port);
server = new TcpListener(localAddr, port);
// Start listening for client requests.
server.Start();
// Buffer for reading data
Byte[] bytes = new Byte[256];
String data = null;
// Enter the listening loop.
while(true)
{
Console.Write("Waiting for a connection... ");
// Perform a blocking call to accept requests.
// You could also user server.AcceptSocket() here.
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Connected!");
data = null;
// Get a stream object for reading and writing
NetworkStream stream = client.GetStream();
int i;
// Loop to receive all the data sent by the client.
while((i = stream.Read(bytes, 0, bytes.Length))!=0)
{
// Translate data bytes to a ASCII string.
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine("Received: {0}", data);
// Process the data sent by the client.
data = data.ToUpper();
byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
// Send back a response.
stream.Write(msg, 0, msg.Length);
Console.WriteLine("Sent: {0}", data);
}
// Shutdown and end connection
client.Close();
}
}
catch(SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
finally
{
// Stop listening for new clients.
server.Stop();
}
Console.WriteLine("\nHit enter to continue...");
Console.Read();
}
}
#using <System.dll>
using namespace System;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Text;
using namespace System::Threading;
void main()
{
try
{
// Set the TcpListener on port 13000.
Int32 port = 13000;
IPAddress^ localAddr = IPAddress::Parse( "127.0.0.1" );
// TcpListener* server = new TcpListener(port);
TcpListener^ server = gcnew TcpListener( localAddr,port );
// Start listening for client requests.
server->Start();
// Buffer for reading data
array<Byte>^bytes = gcnew array<Byte>(256);
String^ data = nullptr;
// Enter the listening loop.
while ( true )
{
Console::Write( "Waiting for a connection... " );
// Perform a blocking call to accept requests.
// You could also user server.AcceptSocket() here.
TcpClient^ client = server->AcceptTcpClient();
Console::WriteLine( "Connected!" );
data = nullptr;
// Get a stream Object* for reading and writing
NetworkStream^ stream = client->GetStream();
Int32 i;
// Loop to receive all the data sent by the client.
while ( i = stream->Read( bytes, 0, bytes->Length ) )
{
// Translate data bytes to a ASCII String*.
data = Text::Encoding::ASCII->GetString( bytes, 0, i );
Console::WriteLine( "Received: {0}", data );
// Process the data sent by the client.
data = data->ToUpper();
array<Byte>^msg = Text::Encoding::ASCII->GetBytes( data );
// Send back a response.
stream->Write( msg, 0, msg->Length );
Console::WriteLine( "Sent: {0}", data );
}
// Shutdown and end connection
client->Close();
}
}
catch ( SocketException^ e )
{
Console::WriteLine( "SocketException: {0}", e );
}
Console::WriteLine( "\nHit enter to continue..." );
Console::Read();
}
有关客户端示例，请参见 TcpClient。
.NET Framework 安全性
- SocketPermission 建立外向连接或接受传入请求。
继承层次结构
System.Object
System.Net.Sockets.TcpListener
线程安全
此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
.NET Compact Framework
受以下版本支持：2.0、1.0