从C ++的gui内部创建的对象修改GUI

Question

I would like to ask about how can I add some text on the screen. I have button, when I click on that, I create new object. It has a function which provide some data for me. How can I acces that data from the gui? I cannot have a getter because it gives me data after some time(after connection to the server). Is there possibilit to put text to textEdit within the object created inside of gui class?

thanks

I adding the code, explaining a little more, sry for confusing, thx for trying to help:

I have EchoClient object created inside of gui class:

void Comunication::startListening(){

    if (this->client == NULL)
       {
           this->client = new EchoClient(QUrl(QStringLiteral("ws://localhost:1234")), 0);
           QObject::connect(client, &EchoClient::closed, this,  &QApplication::quit);

    }
       else
           qWarning() << "Carefull, the client is already running";
   }

then in my EchoClient i have function

  void EchoClient::onTextMessageReceived(QString message)
{
    if (!m_debug)
        qDebug() << "Message received:" << message;

HERE I would like to change the ui stuff.

}

Answer 1

Yes, It's possible. But your question at the moment seems too broad or unclear [at least] to me. I assume that you're using Qt Creator with its designer. So you should be able to access a ui object (in your MainWindow class). Having this object in hand you can change UI at anytime and at anywhere.

So, first assign that text box (ie QLineEdit ) an id (for example myLineEdit ). Now, ui->myLineEdit gives you a QLineEdit * which is actually a reference to that text box. So wherever you'd like to update UI, you should have that reference. For example if you're using TCP socket programming for contacting remote services, in onReadyRead signal of a QTcpSocket , you can update the text box with data you just received:

QLineEdit *textbox = ui->myLineEdit;
textbox->setText("updated data");

Answer 2

I solved this problem with a getter and setter and another button

First button: start listening...creates EchoClient object, this opens the websocket, connects to websocket server. In case the message has arrived from server it goes to method from EchoClient class called onTextMessageRecieved, there it sets atribute message to the value of incoming message.

void EchoClient::onTextMessageReceived(QString message)
{
    if (!m_debug)
        qDebug() << "Message received:" << message;

    setData(message); //setting atribute message
}

Second button: get data... this will call get method from EchoClient class. Comunication is my gui class.

void Comunication::on_getData_clicked()
{
    ui->textEdit_2->setText(this->client->getData());
}

But this solution is not good enough, could yo please advice how to make it that as soon as there is new message my textEdit will be automaticly updated? Should I do it in another thread? I dont have much experiences.

Thanks.