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Hi,

I have a problem with the readLine function. It doesn't work while the computer is connected to the server. I have checked that the computer is connected to the server with the telnet command. I have modified the Fortune Client example, removed the readFortune-function and added a readLine() in the requestNewFortune. The last function is renamed to read_data. I have also added a waitForconnected test before the canReadLine test, but the if (canReadLine ) still fails. I have also tried to remove the if canReadLine test, but the readLine doesn't read anything. The program consists of three files: client.cpp, client.h, main.cpp
The data I'm trying to read looks like this: A new line is available each second, so the problem can't be that readline() can't find \n in the data.

$IIMWV,063,R,001.16,M,A*13
$IIMWV,042,R,002.66,M,A*14
$IIMWV,033,R,002.67,M,A*13
$IIMWV,041,R,001.71,M,A*12

My problem is that the client connects, but it's impossible to read the data.

The data comes with LF and CR, so the canReadLine function should detect a line available for reading.

Run example, output to terminal -terminated with quitbutton.

function read_data()
after connectToHost
wait for connected loop
function read_data()
after connectToHost
wait for connected loop
function read_data()
after connectToHost
wait for connected loop
function read_data()
after connectToHost
wait for connected loop
<Quit>



Any help is deeply appreciated, thanks in advance!

Regards
gQt


client.cpp:

#include <QtGui>
#include <QtNetwork>
#include "client.h"
#include <iostream.h>
#include <QtCore>
#include <qdebug.h>
Client::Client(QWidget *parent)
: QDialog(parent)
{
hostLabel = new QLabel(tr("&Server name:"));
portLabel = new QLabel(tr("S&erver port:"));
hostLineEdit = new QLineEdit("");
portLineEdit = new QLineEdit("");
portLineEdit->setValidator(new QIntValidator(1, 65535, this));

hostLabel->setBuddy(hostLineEdit);
portLabel->setBuddy(portLineEdit);
statusLabel = new QLabel(tr("This examples requires that you run the "
"Fortune Server example as well."));

getFortuneButton = new QPushButton(tr("Get Fortune"));
getFortuneButton->setDefault(true);
getFortuneButton->setEnabled(false);

quitButton = new QPushButton(tr("Quit"));

tcpSocket = new QTcpSocket(this);

connect(hostLineEdit, SIGNAL(textChanged(const QString &)),
this, SLOT(enableGetFortuneButton()));
connect(portLineEdit, SIGNAL(textChanged(const QString &)),
this, SLOT(enableGetFortuneButton()));
connect(getFortuneButton, SIGNAL(clicked()),
this, SLOT(read_data()));
connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));
connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(read_data()));
connect(tcpSocket, SIGNAL(error(QAbstractSocket:ocketError)), this, SLOT(displayError(QAbstractSocket:ocketError)));

QHBoxLayout *buttonLayout = new QHBoxLayout;
buttonLayout->addStretch(1);
buttonLayout->addWidget(getFortuneButton);
buttonLayout->addWidget(quitButton);

QGridLayout *mainLayout = new QGridLayout;
mainLayout->addWidget(hostLabel, 0, 0);
mainLayout->addWidget(hostLineEdit, 0, 1);
mainLayout->addWidget(portLabel, 1, 0);
mainLayout->addWidget(portLineEdit, 1, 1);
mainLayout->addWidget(statusLabel, 2, 0, 1, 2);
mainLayout->addLayout(buttonLayout, 3, 0, 1, 2);
setLayout(mainLayout);

setWindowTitle(tr("Fortune Client"));
portLineEdit->setFocus();
}

void Client::read_data()
{
getFortuneButton->setEnabled(true);
cout << "function read_data()\n";
tcpSocket->abort();
tcpSocket->connectToHost(hostLineEdit->text(),
portLineEdit->text().toInt());

cout << ("after connectToHost\n");

if(tcpSocket->waitForConnected(-1))
{
cout <<"wait for connected loop\n";
if(tcpSocket->canReadLine())
{
mystring=tcpSocket->readLine();
qDebug() << "READ" << mystring;
cout <<"canReadLine loop after readLine\n";
}
statusLabel->setText(mystring);
getFortuneButton->setEnabled(false);
}

}
void Client::displayError(QAbstractSocket:ocketError socketError)
{
switch (socketError) {
case QAbstractSocket::RemoteHostClosedError:
break;
case QAbstractSocket::HostNotFoundError:
QMessageBox::information(this, tr("Fortune Client"),
tr("The host was not found. Please check the "
"host name and port settings."));
break;
case QAbstractSocket::ConnectionRefusedError:
QMessageBox::information(this, tr("Fortune Client"),
tr("The connection was refused by the peer. "
"Make sure the fortune server is running, "
"and check that the host name and port "
"settings are correct."));
break;
default:
QMessageBox::information(this, tr("Fortune Client"),
tr("The following error occurred: %1.")
.arg(tcpSocket->errorString()));
}

getFortuneButton->setEnabled(true);
}

void Client::enableGetFortuneButton()
{
getFortuneButton->setEnabled(!hostLineEdit->text().isEmpty()
&& !portLineEdit->text().isEmpty());
}



client.h:



#ifndef CLIENT_H
#define CLIENT_H
#include <QDialog>
#include <QTcpSocket>
#include <QAbstractSocket>

class QDialogButtonBox;
class QLabel;
class QLineEdit;
class QPushButton;
class QTcpSocket;
class Client : public QDialog
{
Q_OBJECT

public:
Client(QWidget *parent = 0);

private slots:
void read_data();
void displayError(QAbstractSocket:ocketError socketError);
void enableGetFortuneButton();

private:
QLabel *hostLabel;
QLabel *portLabel;
QLabel *cLabel;
QLineEdit *hostLineEdit;
QLineEdit *portLineEdit;
QLabel *statusLabel;
QPushButton *getFortuneButton;
QPushButton *quitButton;
QDialogButtonBox *buttonBox;

QTcpSocket *tcpSocket;
QString currentFortune;
QString mystring;
quint16 blockSize;

};

#endif

main.cpp

#include <QApplication>
#include "client.h"

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Client client;
client.show();
return client.exec();
}

The problem was that I had to add a waitForReadyRead loop inside the waitForConnected loop, then it worked.