Compilation issue with qt_screen

SGaist

Hi and welcome to devnet,

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victor wang

@SGaist
Thanks for telling me .
This is what i got for my error

../../work/mainwindow.cpp: In constructor 'MainWindow(QWidget)': 
../../work/mainwindow.cpp:63:31: 
error: 'qt_screen' was not declared in this scope ui->stackedWidget->resize(qt_screen->deviceWidth(),qt_screeb->deviceHeight());

And this is part of my code

MainWindow::MainWindow(QWidget *parent) : 
QMainWindow(parent),
ui(new Ui::MainWindow)
{
   ui->setipUi(this);
   setWindowFlags(Qt::CustomizeWindowHint);
   ui->stackedWidget->resize(qt_screen->deviceWidth().qt_screen->deviceHeight());
   ui->stackedWidget->setCurrentWidget(ui->stackedWidgetPageMain);

   initPageMain();

   touch=new Touch();
   powerButton=new PowerButton();
   auxButton=new AuxButton();
   usbOtg=new UsbOtg();
   battery=new Battery();
   panel=new Panel();
   lan=new Lan();
   hPattern= new HPattern();
   lodLog=new LodLog();
   record=new Record();
   led=new Led();
   lightsensor=new LightSensor();
}

jsulm

@victor-wang What is qt_screen and where was it declared?

victor wang

@jsulm
I thought that qt_screen no need to be declared.
Because when i get this Sample code， it doesn't seem to be declared.
According to that i search the Example code on Qt website, they do the same thing as below

So i don't think it is the problem.

Hung Tran

@jsulm Something wrong in this code ?
ui->stackedWidget->resize(qt_screen->deviceWidth().qt_screen->deviceHeight());

SGaist

A sample code is not necessarily a fully functioning example.

Also, it's C++, you can't use something that wasn't declared and depending on how you declared it, it also need to be initialized.

jsulm

@Hung-Tran The error message actually tells you what is wrong. qt_screen is not declared.
Add

private:
QScreen qt_screen;

to your MainWindow class.

victor wang

@jsulm
It doesn't work and more error now.
This is what i got for my error

I have tried to add this function

QScreen *qt_screen;

But actually it won't work because deviceWeight() is not the member.
Still got error.

jsulm

@victor-wang I cannot see the screenshot (images do not work here usually).
Did you include QScreen class in your MainWindow header?
deviceWeight() is not member of QSreen this is correct. I guess the example you're using is older?
Check the documentation: http://doc.qt.io/qt-5/qscreen.html
You need to use something else (http://doc.qt.io/qt-5/qscreen.html#geometry-prop ?).

Note: QScreen *qt_screen; is not a function, it is variable declaration.

victor wang

@SGaist
I'm thinking if it is possible to use Qscreen to show the full screen?
I can use the other way to achieve my goal.

SGaist

Following what you wrote, it looks like you should rather take a look at QDesktopWidget.