CODEWITHSUNDEEP
qtqtcpsocketqtcpserver
lena
lena

Reputation: 1191

How to send and read string lines via QTcpSocket?

I try to send strings from client to server line by line in a foreach loop:

foreach(QString s, stringlist)
   client.sendMessage(s);

But the client receives only first string. When I remove "\n" from a string, server receives a bunch of strings merged together in one big string. I thought that adding "\n" would divide the data to strings which I can read with readLine(). What have I missed?

My client

class cClient:public QTcpSocket
{
public:
    void sendMessage(QString text)
    {
        text = text + "\n";
        write(text.toUtf8());        
    }
};

and server:

class pServer:public QTcpServer
{
    Q_OBJECT
public:
    pServer()
    {
        connect(this,SIGNAL(newConnection()),SLOT(slotNewConnection()));
    }

public slots:
    void slotNewConnection()
    {
        QTcpSocket* c = nextPendingConnection();
        connect(c,SIGNAL(readyRead()),this, SLOT(readData()));
    }

    void readData()
    {
        QTcpSocket* conn = qobject_cast<QTcpSocket*>(sender());
        QString data = QString(conn->readLine());
    }
};

Upvotes: 1

Views: 6047

Answers (1)

talamaki
talamaki

Reputation: 5472

You are probably receiving more than one line at the time but only reading the first one. Read as many lines as available by checking with canReadLine. Something like that:

void readData()
{
    QTcpSocket* conn = qobject_cast<QTcpSocket*>(sender());
    QStringList list;
    while (conn->canReadLine())
    {
        QString data = QString(conn->readLine());
        list.append(data);
    }     
}

Upvotes: 3

Related Questions