QTcpSocket，无法读取传入数据

Posted 2023-02-16

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【中文标题】QTcpSocket，无法读取传入数据【英文标题】：QTcpSocket, can't read incoming data 【发布时间】：2014-05-11 12:03:59 【问题描述】：

我尝试使用 Qt 和 C++ 编写简单的服务器。这是代码：

   #include "mytcpserver.h"

MyTcpServer::MyTcpServer(QObject *parent) :
    QObject(parent)

    server = new QTcpServer(this);


    // whenever a user connects, it will emit signal
    connect(server, SIGNAL(newConnection()),
            this, SLOT(newConnection()));



    if(!server->listen(QHostAddress("127.0.0.1"), 3333))
    
        qDebug() << "Server could not start";
    
    else
    
        qDebug() << "Server started!";
    


   void MyTcpServer::on_readyRead()
  
QTcpSocket * senderSocket = dynamic_cast<QTcpSocket *>(sender());
if (senderSocket)

    qDebug() << "reading data";
    qDebug() << senderSocket->readAll();

  

  void MyTcpServer::newConnection()

    // need to grab the socket
QTcpSocket *sok=new QTcpSocket();
sok = server->nextPendingConnection();
if (sok)

    connect(sok,SIGNAL(readyRead()),this,SLOT(on_readyRead()));
    connect(sok,SIGNAL(disconnected()),sok,SLOT(deleteLater()));

sok->write("Writing");

以及 php 客户端的一部分：

$address = "127.0.0.1";
$service_port = "3333";
echo "Attempting to connect to '$address' on port '$service_port'...";
$result = socket_connect($socket, $address, $service_port);
if ($result === false) 
    echo "socket_connect() failed.\nReason: ($result) " . socket_strerror(socke$
 else 
    echo "OK.\n";


$in = "HEAD / HTTP";
$out = '';

echo "Sending HTTP HEAD request...";
socket_write($socket, $in, strlen($in));
echo "OK.\n";
echo "Reading response:\n\n";
while ($out = socket_read($socket, 2048)) 
    echo $out;

问题是我无法从 php 客户端读取，具体来说，没有发出信号 readyRead。此外，如果我尝试输入命令行： telnet 127.0.0.1 3333 则服务器仅响应“Writing”并退出。

【问题讨论】：

您从类中删除了 sok，而不是 newConnection() 中的局部变量。现在 readyRead 信号没有连接到任何东西。从 nextPendingConnection() 获得套接字后立即连接从 nextPendingConnection 获取传入连接后，您将立即关闭它！你期望它如何接收数据？不要关闭它！ on_readyRead() 中的 sok 指的是什么？？ 【参考方案1】：

试试这个：

#include "mytcpserver.h"

MyTcpServer::MyTcpServer(QObject *parent) :
    QObject(parent)

    server = new QTcpServer(this);

    // whenever a user connects, it will emit signal
    connect(server, SIGNAL(newConnection()), this, SLOT(newConnection()));


    if(!server->listen(QHostAddress("127.0.0.1"), 3333))
    
        qDebug() << "Server could not start";
    
    else
    
        qDebug() << "Server started!";
    


void MyTcpServer::on_readyRead()
 
    QTcpSocket * senderSocket = dynamic_cast<QTcpSocket*>(sender());
    if(senderSocket)
    
        qDebug() << "reading data";
        qDebug() << senderSocket->readAll();
    


void MyTcpServer::newConnection()

    // need to grab the socket
    QTcpSocket * newSocket = server->nextPendingConnection();
    if(newSocket)
    
        connect(newSocket ,SIGNAL(readyRead()),this,SLOT(on_readyRead()));

        //Additionnal auto clean-up without keeping track of the pointer
        connect(newSocket ,SIGNAL(disconnected()),newSocket ,SLOT(deleteLater()));

（当你声明这个时：