sometimes qt was ended forcefully, weird.

[circle]

@Christian-Ehrlicher
thanks, i am not 100% sure about that answer, but i will try another solution. now the question is, where do i get the size of centralwidget automatically when QMainWindows is in fullscreen (showFullScreen() in c'tor)? i tried showEvent and C'tor but failed to get the right size.

[JonB]

@circle
I admit I have not tried it but I would have expected it in showEvent() as we discussed earlier. Could you show where you put what code for that?

[Christian Ehrlicher]

I still don't understand the need to know the size of a widget at all - your code you showed us doesn't do anything with it. Use layouts...

[circle]

@JonB
qDebug to print the line and ui->centralwidget->width()

[circle]

@Christian-Ehrlicher
well, i am supposed to do some complicated drawings as the background based on the size of centralwidget, there maybe several different solutions and i never use layouts before. those code was migrated from windows.

[JonB]

@circle said in sometimes qt was ended forcefully, weird.:

qDebug to print the line and ui->centralwidget->width()

Can you show just the few lines of code where you do this? What method it's in and where you do it.

[Christian Ehrlicher]

@circle said in sometimes qt was ended forcefully, weird.:

i am supposed to do some complicated drawings as the background

You can't draw on a widget outside the paintEvent()...

[circle]

@JonB said in sometimes qt was ended forcefully, weird.:

@circle said in sometimes qt was ended forcefully, weird.:

qDebug to print the line and ui->centralwidget->width()

Can you show just the few lines of code where you do this? What method it's in and where you do it.

void MainWindow::showEvent(QShowEvent * event)
{
    QMainWindow::showEvent(event);
    qDebug() << "w: " << ui->centralwidget->width() << "h: " << ui->centralwidget->height();
}

[circle]

@Christian-Ehrlicher said in sometimes qt was ended forcefully, weird.:

@circle said in sometimes qt was ended forcefully, weird.:

i am supposed to do some complicated drawings as the background

You can't draw on a widget outside the paintEvent()...

maybe paintEvent() is a better way, but i'm using eventFilter() instead (i am new to qt), more specifically, most of drawings are in the memory, such as qpixmap, qpainterpath, and they are working fine.

[Christian Ehrlicher]

But not in your example you show above - there you do a lot of stuff which doesn't belong to a resize (or paint)Event. I gave you a lot of examples on how to change it. Giving up.