Connect two windows

[joojo]

i want to create two windows and connect how can i do?

[qxoz]

Hi joojo!
Welcome to devnet.

It depends. You need two window in one app or two separate apps?

[joojo]

i want to click button in main window and pop up new window.then i do calculations in 2 nd window and submit.then change main window values.

[qxoz]

Well then then just create the method in second dialog end call it after dialog closed:
@void on_showdialog_action()
{
uSecondDialog *usrDlg = new uSecondDialog(this);
if(usrDlg->exec() == QDialog::Accepted)
{
uCalcResultStruct result = usrDlg->getCalcResult();
}
}@

Something like that.
uCalcResultStruct is some your struct which can store all data you need.