QWidget

[mickey]

Hi, I inserted this code in main.cpp; but button doesn't appear..Why?
Thanks
QWidget mw2;
mw2.setGeometry(800,200,200,400);
QButton* quit2 = new QButton(&mw2);
quit2->setGeometry(0,0,10,10);
mw2.show();

[wysota]

Because you created the widget on stack and it got destroyed before it had a chance to reveal itself.

[mickey]

but why was it destroyed, please?

[jacek]

but why was it destroyed, please?
Probably because it went out of scope. Did you put that code inside an if statement or a loop body?

[mickey]

only button don't appear; widget is visible! I insert it in main() function...

[wysota]

Maybe you should use QPushButton instead of QButton?