Opening dynamically created buttons

[Romi11]

I tried to make some dynamically created buttons but the appllication closed when I try to do it or make every buttons in one position in a frame (when a I do it in new window it works but I need in a special created frame several buttons)

void MainWindow::createButtons(){

QVBoxLayoutlayout=qobject_cast<QVBoxLayout>(ui->frame->layout());
//this line makes a problem

// QVBoxLayout *layout=new QVBoxLayout(); //this works

QPushButton *przyc =new QPushButton(buttontext, ui->frame);
layout->insertWidget(1,przyc);
QPushButton *przyc2 =new QPushButton(buttontext, ui->frame);
layout->insertWidget(2,przyc2)
przyc->show();
przyc2->show();

}

My QT creator 2.7.2 on base qt 5.1.0 version under linux mint

[SGaist]

Hi and welcome to devnet,

@Romi11 said in Opening dynamically created buttons:

QVBoxLayoutlayout=qobject_cast<QVBoxLayout>(ui->frame->layout());

You do not check whether the value is null.

I guess that you did not apply a layout on your frame in designer.

[Romi11]

You right the pointer is null however I applied in Qt creator layout and frame . How to do it correctly?

[mrjj]

@Romi11

Hi
Go to Designer and look what the Layout really is named.

Then it's available as
ui->verticalLayout

and see if that works;

Also you can avoud casting as its of correct layout type already.

[Romi11]

now it works how I supposed. I think its difficult to achieve it, without your support I would have spent many hours until find it correctly

[mrjj]

@Romi11
Hi
Well, Its unclear why layout() didn't work.
It does return the layout for me in a small example.

So I think maybe you changed the type of the layout
and hence when you cast it becomes zero as it was not the right type.

Or something like that.

[Romi11]

@mrjj I think I do it how in example but the philosophy of qt frames and layouts I should to learn more.
Thanks for quick answers :)