How to Center a Window on the Screen

[gapry]

Development Environment

1. Linux Y410P 4.14.71-1-MANJARO #1 SMP PREEMPT x86_64 GNU/Linux
2. Qt Creator 4.7.0
3. Based on Qt 5.11.1 (GCC 8.2.0, 64 bit)

I use the wiki approach[1] to center the window which is a QWidget on the screen and Qt Creator show the following warning message.

'availableGeometry' is deprecated: Use QGuiApplication::screens()

I check the official document[2] and find QGuiApplication::screens() will return QList<QScreen *>.

According the document of QScreen Class [3], it provides geometry() to return QRect.

So I try this code auto screenGeometry = QGuiApplication::screens().first()->geometry(); and it occurs the following error message.

member access into incomplete type 'QScreen'

And suggestion?

Thanks

References

1. How to Center a Window on the Screen
2. QList<QScreen *> QGuiApplication::screens()
3. QScreen Class

[Christian Ehrlicher]

@gapry said in How to Center a Window on the Screen:

member access into incomplete type 'QScreen'

QScreen is not known to the compiler (except that it knows that it's a class) - so you should include the header where the QScreen class is defined.

[SGaist]

Hi,

@Christian-Ehrlicher said in How to Center a Window on the Screen:

@gapry said in How to Center a Window on the Screen:

member access into incomplete type 'QScreen'

QScreen is not known to the compiler (except that it knows that it's a class) - so you should include the header where the QScreen class is defined.

@Christian-Ehrlicher Didn't you mean where the QScreen class is used in your application ?

[gapry]

Well, I make a idiot mistake. I forget do this #include <QScreen>.

It can solve the issue. Thank you.

[Christian Ehrlicher]

@SGaist said in How to Center a Window on the Screen:

where the QScreen class is used in your application

Yes :)

@gapry : Please mark the thread as fixed