Bind Timer with a bool variable.

thomasGl

Ok, thx i forgot to include <QDebug>

thomasGl

Hey Guys. Now i am trying to hide my label when my counter ist 5. My counter increases when i click the Button. I made a function where "this->hide(); <----"this" is my label. I am calling that function inside onother function in my Buttonclass, but the program crashes.

QObject::connect(this,SIGNAL(clicked(bool)),this,SLOT(ButtonclickedXtimes()));  //i am connecting the Button with the function for counting

void Button::ButtonclickedXtimes()   //slot function 
{
    Label* l;

   count++;
   qDebug()<<count;

   if(count==5)
   {
       l->labelhide();   //here i am calling the function for the label to hide.
   }


}
/*****************Label Class********************/

Label::Label(QWidget *parent):QLabel(parent)
{
    this->setGeometry(200,200,200,200);       
    this->setText("Hello World");        //i want that text to hide when counter is 5

    
 void Label::labelhide()    //thats my label hide function
{
    this->hide();
}

Christian Ehrlicher

@thomasGl said in Bind Timer with a bool variable.:

but the program crashes.

    Label* l;

   count++;
   qDebug()<<count;

   if(count==5)
   {
       l->labelhide();

I would be surprised if it would not crash.
The same as in your first post - you're using an unitialized pointer so what do you expect?

thomasGl

i initialized it with NULL , it crashes after 5 .

Christian Ehrlicher

@thomasGl said in Bind Timer with a bool variable.:

i initialized it with NULL , it crashes after 5 .

Are you kidding me?
It must be a valid pointer to your label you want to show or hide...

JonB

@Christian-Ehrlicher Listen, at least it is initialized... ;-)

thomasGl

@JonB said in Bind Timer with a bool variable.:

;-)

xD i got this thx guys.

thomasGl

Hi, how do i connect that button to the slots onclicked();?

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

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QMainWindow* wind = new QMainWindow();
    wind->resize(500,500);


    tWindow*z=new tWindow;

    //create Button
    QPushButton* butt = new QPushButton(wind);  
    butt->setText("click");


    QLabel* labb = new QLabel(wind);
    labb->setText("hello World");
    labb->setGeometry(200,200,200,200);

    //QObject::connect(button,SIGNAL(clicked(bool)),&a,SLOT(quit()));

    QObject::connect(butt,SIGNAL(clicked(bool)),tWindow,SLOT(onClicked())); //<-----this

#include "twindow.h"

tWindow::tWindow(QWidget *parent):QMainWindow(parent)
{


}

tWindow::~tWindow()
{

}

void tWindow::onClicked()    //<----to this slot.
{
    qDebug()<<"HELLO";
}

jsulm

@thomasGl

connect(butt, &QPushButton::clicked, z, &tWindow::onClicked);

Please read https://doc.qt.io/qt-6/signalsandslots.html

JonB

@thomasGl said in Bind Timer with a bool variable.:

QObject::connect(butt,SIGNAL(clicked(bool)),tWindow,SLOT(onClicked())); //<-----this

Please do yourself a favor and only use New Signal Slot Syntax. "Old style" with SIGNAL/SLOT() macros is like a decade out of date nowadays!

QObject::connect(butt, &QPushButton::clicked, tWindow, &tWindow::onClicked);

It is then optional whether you make your tWindow::onClicked() method take the bool parameter --- if you don't care about the "checked" state you don't have to bother. A slot may have fewer parameters than the signal, but never more.

Having said this: your error is that tWindow is your class (shame you start it with a lowercase letter, very confusing), your instance is z so you will actually want

QObject::connect(butt, &QPushButton::clicked, z, &tWindow::onClicked);

thomasGl

i understand thx.

thomasGl

Because of Q_Object i am getting an error: undefined reference to vtable for lablos and error: Id returned 1 exit status. How can i fix that. I need Q_Object.

#ifndef LABLOS_H
#define LABLOS_H

#include <QLabel>

class lablos:public QLabel
{
    Q_OBJECT      //<----because of Q_Object i am getting an error..


public:
    lablos(QWidget* parent);


};

#endif // LABLOS_H

Pl45m4

@thomasGl

Re-run qmake / cmake after you added the Q_OBJECT macro

thomasGl

@Pl45m4 qmake / cmake? what do u mean?

Pl45m4

@thomasGl

You are using probably one of them. It's the build tool that "Makes" your code and builds your app / executable from your source code.

Especially when you add the QObject macro to some classes, you have to re-run it, to ensure that everything is updated. Sometimes your IDE (like QtCreator) notices, sometimes it doesn't.

thomasGl

Thank you it works.

thomasGl

Hi, i stuck again. I am trying to show my label after 5 clicks on my Pushbutton else label should hide. How can i count 1 click after 1 click? My problem is the loop i have only managed to get 5 counts with no click. I need 1 count with 1 click on the button. I tried to put QObject::connect(but, &Button::clicked, but,&Button::count); in my loop instead of "but->count" but it does not work. Do i need a mousepressevent here?

void Button::count()              //thats my method i have connected with my Button
{
    counter++;
     qDebug()<<counter;
}


QObject::connect(but, &Button::clicked, but,&Button::count);    //Connection



    while (but->counter!=5)   //my loop
    {
        if(but->counter==5)
        {
            labb->show();
        }
        else
        {
           but->count();    //here i want to click and count
        }
    }

Pl45m4

@thomasGl

The while loop blocks your counting on click. You dont need it.

Add something like

QObject::connect(but, &Button::clicked, this ,&MainWindow::onCount);


MainWindow::onCount{
if(but->counter==5)
        {
            labb->show();
        }

}

thomasGl

Hey. I how can i make that label to show my counter?

void mainWin::onCount()
{
    if(counter==4)
    {
        labb->show();
        labb->setText("Hello World");
    }


    counter++;
    
    qDebug()<<counter;    //i want that counter to be shown with that label2
    
    label2->setText(counter);  //i want that label to show my  counter



}

jsulm

@thomasGl said in Bind Timer with a bool variable.:

//i want that label to show my counter

Then convert it to a string first using https://doc.qt.io/qt-6/qstring.html#number ...