QApplication::desktop()->screenGeometry() not work in qt6

[timob256]

I'm trying to find out the screen size.

Previously, I recognized with one command, but now it does not work.

 QRect size = QApplication::desktop()->screenGeometry();  
 this->resize(size.width() * 0.25, size.height() * 0.25);

but QApplication::desktop() not work this now ;_:

i traing using

QSize size = screen->availableSize();
this->resize(size.width() * 0.25, size.height() * 0.25);

but this hot work

How to find out the screen size now ???

[A.A.SEZEN]

try this

QGuiApplication::primaryScreen()->geometry()

[jsulm]

@timob256 said in QApplication::desktop()->screenGeometry() not work in qt6:

size

What is its value?

[A.A.SEZEN]

try this

QGuiApplication::primaryScreen()->geometry()

[timob256]

@jsulm

#include "mainwindow.h"

mainwindow::mainwindow(QWidget *parent)
    : QWidget{parent}
    , wgt (new wgt_screen(this))
{
    QSize size1 = screen->availableSize();   // error
    this->resize(size1.width() * 0.25, size1.height() * 0.25);


  QRect size = QApplication::desktop()->screenGeometry();  // error
    this->resize(size.width() * 0.25, size.height() * 0.25);

    gridlayout = new QGridLayout(parent);
    gridlayout->addWidget(wgt);

    this->setLayout(gridlayout);
}

CMakeList.txt

cmake_minimum_required(VERSION 3.5)

project(wgt_screen_turbo VERSION 0.1 LANGUAGES CXX)

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(Qt6 COMPONENTS Widgets REQUIRED)
find_package(QT NAMES Qt6 Qt5 COMPONENTS Widgets REQUIRED)
find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Widgets REQUIRED)

set(PROJECT_SOURCES
#        main.cpp
#        wgt_screen.cpp
#        wgt_screen.h
examples/main.cpp
examples/mainwindow.h
examples/mainwindow.cpp
src/wgt_screen.cpp
src/wgt_screen.h
)

if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
    qt_add_executable(wgt_screen_turbo
        MANUAL_FINALIZATION
        ${PROJECT_SOURCES}
    )
# Define target properties for Android with Qt 6 as:
#    set_property(TARGET wgt_screen_turbo APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
#                 ${CMAKE_CURRENT_SOURCE_DIR}/android)
# For more information, see https://doc.qt.io/qt-6/qt-add-executable.html#target-creation
else()
    if(ANDROID)
        add_library(wgt_screen_turbo SHARED
            ${PROJECT_SOURCES}
        )
# Define properties for Android with Qt 5 after find_package() calls as:
#    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
    else()
        add_executable(wgt_screen_turbo
            ${PROJECT_SOURCES}
        )
    endif()
endif()

target_link_libraries(wgt_screen_turbo PRIVATE Qt${QT_VERSION_MAJOR}::Widgets)
target_link_libraries(wgt_screen_turbo PRIVATE Qt6::Widgets)

set_target_properties(wgt_screen_turbo PROPERTIES
    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
)

if(QT_VERSION_MAJOR EQUAL 6)
    qt_finalize_executable(wgt_screen_turbo)
endif()

[jsulm]

@timob256 said in QApplication::desktop()->screenGeometry() not work in qt6:

// error

What error?

[Christian Ehrlicher]

@jsulm said in QApplication::desktop()->screenGeometry() not work in qt6:

What error?

You have to know this ! I mean - is your crystal ball not working today?

Educated guess: If you want to use QDesktopWidget you should insert the header where the class is defined - basic C

[geodoomgr]

I had a similar problem, as I was trying to build the small project of
https://github.com/LAmmeraal/sourceCode/blob/master/changeline.cpp
in Qt6 , I could see the error, and in the end what I did is substituting the line:

//QRect rec = QApplication::desktop()->screenGeometry();  // for Qt5
QRect rec = QApplication::primaryScreen()->geometry();  // Qt6 , along with the #include <QScreen> at the top

[RaKa]

@geodoomgr: your tip helped, now works great on QT 6.6.3 thanks