Button does nothing

homnislash

Hi all, okay, now I have a push button on the app but it can do nothing :(
I tried several methods, but nothing seem to activate it:

I tried this tuto: https://www.youtube.com/watch?v=VigUMAfE2q4&ab_channel=ProgrammingKnowledge
and this one: https://www.youtube.com/watch?v=dOovH6TvaY4&ab_channel=VoidRealms

Any help please? To make something that works a bit?

homnislash

You're absolutly right! I changed it to a textEdit, it compiles nicely :)

SGaist

Hi,

Please show your code.

That said, beside YouTube, the Qt documentation is full of examples to get you started. You might want to dig in it a bit.

JonB

@homnislash
Not many people here are going to want to watch videos. The idea is you show a bit of code --- code you can paste --- you are trying. And you explain what is wrong or what is not working.

homnislash

Thank you so much for your help, I could display some text through the button clic via this tuto :
https://www.youtube.com/watch?v=Pb-XC5Q5zLU&ab_channel=ParwizForogh

Here is a snippet of my code to illustrate: the cpp file:

#include "mybutton.h"
#include "./ui_mybutton.h"

MyButton::MyButton(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MyButton)
{
    ui->setupUi(this);
}

MyButton::~MyButton()
{
    delete ui;
}


void MyButton::on_pushButton_clicked()
{
    ui->lineEdit->setText("Hi");
}

I had a hard time trying to have an interaction to find a solution to display some text. See you soon!

Christian Ehrlicher

Please show the content of ui_mybutton.h and also please don't use the auto-connect feature but do the connects by yourself.

homnislash

@Christian-Ehrlicher Thanks for the reply, I am not sure to understand, I have a .h file, is this what you want to see?

#ifndef MYBUTTON_H
#define MYBUTTON_H

#include <QMainWindow>

QT_BEGIN_NAMESPACE
namespace Ui { class MyButton; }
QT_END_NAMESPACE

class MyButton : public QMainWindow
{
    Q_OBJECT

public:
    MyButton(QWidget *parent = nullptr);
    ~MyButton();

private slots:
    void on_pushButton_clicked();

private:
    Ui::MyButton *ui;
};
#endif // MYBUTTON_H

JonB

@homnislash
The file requested is the ui_mybutton.h one, not the mybutton.h you show. It should be in the build directory you are compiling in, not the source directory. It is the result of running uic on the .ui file which was saved from Designer.

homnislash

thanks for clarifying, here you go:

/********************************************************************************
** Form generated from reading UI file 'mybutton.ui'
**
** Created by: Qt User Interface Compiler version 6.4.0
**
** WARNING! All changes made in this file will be lost when recompiling UI file!
********************************************************************************/

#ifndef UI_MYBUTTON_H
#define UI_MYBUTTON_H

#include <QtCore/QVariant>
#include <QtWidgets/QApplication>
#include <QtWidgets/QHBoxLayout>
#include <QtWidgets/QMainWindow>
#include <QtWidgets/QMenuBar>
#include <QtWidgets/QPushButton>
#include <QtWidgets/QStatusBar>
#include <QtWidgets/QTextEdit>
#include <QtWidgets/QWidget>

QT_BEGIN_NAMESPACE

class Ui_MyButton
{
public:
    QWidget *centralwidget;
    QWidget *widget;
    QHBoxLayout *horizontalLayout;
    QTextEdit *textEdit;
    QPushButton *pushButton;
    QMenuBar *menubar;
    QStatusBar *statusbar;

    void setupUi(QMainWindow *MyButton)
    {
        if (MyButton->objectName().isEmpty())
            MyButton->setObjectName("MyButton");
        MyButton->resize(800, 600);
        centralwidget = new QWidget(MyButton);
        centralwidget->setObjectName("centralwidget");
        widget = new QWidget(centralwidget);
        widget->setObjectName("widget");
        widget->setGeometry(QRect(50, 5, 222, 211));
        horizontalLayout = new QHBoxLayout(widget);
        horizontalLayout->setObjectName("horizontalLayout");
        horizontalLayout->setContentsMargins(0, 0, 0, 0);
        textEdit = new QTextEdit(widget);
        textEdit->setObjectName("textEdit");

        horizontalLayout->addWidget(textEdit);

        pushButton = new QPushButton(widget);
        pushButton->setObjectName("pushButton");

        horizontalLayout->addWidget(pushButton);

        MyButton->setCentralWidget(centralwidget);
        menubar = new QMenuBar(MyButton);
        menubar->setObjectName("menubar");
        menubar->setGeometry(QRect(0, 0, 800, 22));
        MyButton->setMenuBar(menubar);
        statusbar = new QStatusBar(MyButton);
        statusbar->setObjectName("statusbar");
        MyButton->setStatusBar(statusbar);

        retranslateUi(MyButton);

        QMetaObject::connectSlotsByName(MyButton);
    } // setupUi

    void retranslateUi(QMainWindow *MyButton)
    {
        MyButton->setWindowTitle(QCoreApplication::translate("MyButton", "MyButton", nullptr));
        pushButton->setText(QCoreApplication::translate("MyButton", "PushButton", nullptr));
    } // retranslateUi

};

namespace Ui {
    class MyButton: public Ui_MyButton {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_MYBUTTON_H

What do you have in mind?

JonB

@homnislash said in Button does nothing:

void MyButton::on_pushButton_clicked()
{
    ui->lineEdit->setText("Hi");
}

I see a slot which I believe will be called correctly.

But I see no widget named lineEdit (or for that matter any QLineEdit) anywhere in the ui_...h file. I would therefore conclude that your statement ui->lineEdit->setText("Hi"); will not compile.

homnislash

You're absolutly right! I changed it to a textEdit, it compiles nicely :)

JonB

@homnislash
You seem like an intelligent person. What I do not understand is that you would/should have got a compiler error. Did you not think it was relevant to say "it does not compile on this line" rather than "button does nothing"? I don't mean to sound rude, just this was terribly relevant!