How to add buttons to a main window in Qt?

Question

I\'m new to qt programming so please don\'t mind if you find it a noob question. I\'ve added a button to my main window but when I run the code the button is not displayed.

Answer 1

In main window you should use central widget . You have two choices :

Set the button for central widget ( Not so good choice ) :

QPushButton *train_button = new QPushButton(this);
train_button->setText(tr("something"));
setCentralWidget(train_button);

Add a widget and add the button to that widget and set the widget for centralWidget :

QWidget * wdg = new QWidget(this);
QPushButton *train_button = new QPushButton(wdg);
train_button->setText(tr("something"));
setCentralWidget(wdg);

And surely you can use Layouts for your centralWidget:

QWidget * wdg = new QWidget(this);
QVBoxLayout *vlay = new QVBoxLayout(wdg);
QPushButton *btn1 = new QPushButton("btn1");
vlay->addWidget(btn1);
QPushButton *btn2 = new QPushButton("btn2");
vlay->addWidget(btn2);
QPushButton *btn3 = new QPushButton("btn3");
vlay->addWidget(btn3);
wdg->setLayout(vlay);
setCentralWidget(wdg);