Signal and slot not working properly

UG SEP

Hey,
I have created a signal and slot that I send data from the second window to the main window
whenever the user clicks the button
But I not sending the signal
Here is the signal in is in main window

 Login log;
    connect(&log,SIGNAL(sendinfo(QString)),this,SLOT(recieveinfo(QString)));

receiveinfo function this also exist in main window

void Mainwindow::recieveinfo(QString username)
{
   name=username;
}

slot in mainwindow.h

public slots:
    void recieveinfo(QString name);

signal in second window.cpp

signals:
 void sendinfo(QString name);

sendinfo emit from push button

emit sendinfo(ui->name->text());

The string name doesn't change means there is a problem in signal and slots
Please help me
Thanks in advance

JonB

@UG-SEP
Start with qDebug() << ui->name->text() just above the emit line and qDebug() << username as first line in Mainwindow::recieveinfo(). Does the slot actually get called?

It is confusing that you have recieveinfo(QString name) in the header declaration but Mainwindow::recieveinfo(QString username) in the definition. Keep those parameter names the same.

In the longer run it is better to pass const QString & parameters than QString, but that won't be the problem here.

And finally do yourself a favor and change over to New Signal Slot Syntax, it will help you in the long run.

J.Hilk

@UG-SEP said in Signal and slot not working properly:

Login log;
connect(&log,SIGNAL(sendinfo(QString)),this,SLOT(recieveinfo(QString)));

this seems like a lifetime problem.

I would bet, that log is beeing destroyed sometime later, at the ‚}

mrjj

Hi
Killed by scope +1

void buttonclick() {
 Login log;
 connect(&log,SIGNAL(sendinfo(QString)),this,SLOT(recieveinfo(QString)));
} // log will be deleted here so sendinfo will never trigger


make  
Login log; 
part of the "second window" as a member, not as a local variable