QTcpServer或QTcpClient在服务器端知道，已连接的客户端现在已断开连接

问题描述

| 在下面的代码中，我可以确定客户端是否已连接，并且在QTableWidget中添加了一行，但是我怎么知道客户端已断开连接，因此我可以从同一表中删除一行断开连接的客户端。

Tcpserver::Tcpserver(QWidget *parent) :QDialog(parent),ui(new Ui::Tcpserver)
{
    ui->setupUi(this);
    m_coSerSo =new CoServerSocket(this);
    count=0;


   connect(m_coSerSo,SIGNAL(newConnection()),this,SLOT(updateConnectionTable()));
 }

 Tcpserver::~Tcpserver()
 {
    delete ui;
 }
 void Tcpserver::updateConnectionTable()
 { 
     int row = ui->tableWidget->rowCount();
     ui->tableWidget->setRowCount(row + 1);
     ui->tableWidget->setItem(row,new QTableWidgetItem(m_coSerSo->getPeerAdd()));
     ui->tableWidget->setItem(row,1,new QTableWidgetItem(QDateTime::currentDateTime ().toString()));
}


CoServerSocket::CoServerSocket(QObject *parent)
    : QTcpserver(parent)
{ peerAdd =\"good1\";

}

void CoServerSocket::incomingConnection(int socketId)
{
    socketClient = new CoClientSocket(this);
    socketClient->setSocketDescriptor(socketId);

    peerAdd =  socketClient->peerAddress().toString();
}
QString CoServerSocket::getPeerAdd()
{
    return peerAdd;
}

    

解决方法

        您在ѭ1inside中创建的套接字具有

disconnected()

信号。使用

QSignalMapper

确定哪个套接字已断开连接并更新表视图。快速而肮脏的代码，可能有用，并且肯定充满语法错误：

TcpServer::TcpServer(QWidget *parent) :
    QDialog(parent),ui(new Ui::TcpServer)
{
    ui->setupUi(this);
    m_coisSerSo = new CoisServerSocket(this);
    count = 0;

    // The mapper forwards the signal from the client socket,// adding the socket itself as an argument.

    this->mapper = new QSignalMapper(this);
    connect(this->mapper,SIGNAL(mapped(QObject*)),this,SLOT(clientDisconnected(QObject*)));


    connect(m_coisSerSo,SIGNAL(newConnection()),SLOT(updateConnectionTable()));
}

void CoisServerSocket::incomingConnection(int socketId)
{
    socketClient = new CoisClientSocket(this);
    socketClient->setSocketDescriptor(socketId);

    // Map the socket so that we can receive its disconnection
    // notification. When the socket emits the \"disconnected()\"
    // signal,the mapper will emit \"mapped(QObject*)\" and will
    // pass the socket as the argument.

    this->mapper->setMapping(socketClient,socketClient);
    connect(socketClient,SIGNAL(disconnected()),this->mapper,SLOT(map()));

    peerAdd =  socketClient->peerAddress().toString();
}

void CoisServerSocket::clientDisconnected(QObject* object)
{
    if (CoisClientSocket* client = qobject_cast<CoisClientSocket*>(object))
    {
        // Unmap the socket.

        this->mapper->removeMappings(client);

        // Handle disconnection here.

        ...

        // A consequence of mixing a TCP server and a dialog in the
        // same class is that passing \"this\" as an argument to the
        // socket constructor doesn\'t help much with memory management. 
        // They will stay around as long as the dialog lives. Delete 
        // them once they aren\'t needed anymore.

        client->deleteLater();
    }
}