How to change size of QWidget by connect(button...)

freelife

Please help with two problems.
1)I need to connect one of buttons of this class with changing size of myWindow by consts. (for exaplme setSize(x*y) ).

@class MyWindow : public QWidget, public Ui::MyWindow
{
Q_OBJECT
//...
}
@
2) And how I can prevent to user to change the size?
@layout()->setSizeConstraint(QLayout::SetFixedSize);@
is't work. It crashes the program:
@
Runs MyWindow.exe ....
The program terminated unexpectedly.
MyWindow.exe exited with code -1073741819
@

beemaster

"QWidget::setFixedSize":http://qt-project.org/doc/qt-4.8/qwidget.html#setFixedSize-2

freelife

Ok, but I need to connect it. That's method, not slot. Sorry for quations like this I have not perfect English.

freelife

@void MyWindow::sizeBigger()
{
this->setFixedSize(477, 250);
groupBox_3->show();
}
void MyWindow::sizeSmoller()
{
this->setFixedSize(477, 180);
groupBox_3 -> hide();
}
@
Is work, thank you! But, after sizeSmoller all groupBoxes become Black.
groupBox_3 - lowest groupBox.
!http://i.imgur.com/iRz9Egdl.jpg(Problem)!