How to make a user not resize a window.

Hello everyone.

I'm not getting a QWidget-based window to stay fixed, without the user resizing it.
Just to level the information I'm using Linux Debian 8.5 64Bits, Qt 5.7.0 (GCC 4.9.1 20140922 (Red Hat 4.9.1-10), 64 bit) and Qt Creator 4.0.2.

Code:

---

frmMainWindow::frmMainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::frmMainWindow)
{
    ui->setupUi(this);
    this->setWindowTitle("Sistema Em Qt");
    this->ui->mainToolBar->setVisible(false);
    this->setCentralWidget(ui->mdiAreaMain);
    this->showMaximized();
}
 
void frmMainWindow::on_actConfig_do_Sistema_triggered()
{
    frmConfigSistema *frmConfigSistemaObj = new frmConfigSistema;
    frmConfigSistemaObj->setFixedSize(740,360);
    frmConfigSistemaObj->setWindowTitle("Configurações do Sistema");
    ui->mdiAreaMain->addSubWindow(frmConfigSistemaObj);
    frmConfigSistemaObj->show();
}

---

I have tried in several ways like:

1) - Not to display the Minimize and Maximize buttons.

Code:

---

Qt::WindowFlags flags ;
 flags |= Qt::CustomizeWindowHint | Qt::WindowCloseButtonHint
 this->setWindowFlags(flags);

---

2) - Fix the size by the code.

Code:

---

frmConfigSistemaObj->setFixedSize(740,360);
frmConfigSistemaObj-> setSizePolicy(QSizePolicy::Fixed,QSizePolicy::Fixed);

---

3) - Fix the size by Qt Creator Property Editor according to PrntScr "Fig - Redimensionamento_1.jpg".



The closest I got was with the code below, but two windows pop up at once. "Fig - Redimensionamento_2.jpg".

Code:

---

frmConfigSistema *frmConfigSistemaObj = new frmConfigSistema;
    frmConfigSistemaObj->setFixedSize(740,360);
    frmConfigSistemaObj->setWindowTitle("Configurações do Sistema");
    ui->mdiAreaMain->addSubWindow(frmConfigSistemaObj);
    Qt::WindowFlags flags = 0;
    frmConfigSistemaObj->setWindowFlags(flags);
    frmConfigSistemaObj->setWindowFlags(Qt::Window | Qt::CustomizeWindowHint | Qt::WindowCloseButtonHint);
    frmConfigSistemaObj->show();

---

Does anyone have any examples that I can follow, or an explanation of what is happening?

Thanks.

Try to set width and height in minimumSize and maximumSize to same size as in Geometry tab.

Hello, ado130.

I had already done this, and nothing happened.
The window continues to be resized.

Thanks.