Building a simple qt project with CMake - c++

Question

I'm trying to build a simple qt project with CMake, which contains main.cxx, MainWindow.cxx and MainWindow.hxx. When I try to make install it says fatal error: 'QMainWindow' file not found, but I do added Widgets in the CMakelists.txt.
Here are the codes:
main.cxx:
#include <QApplication>
#include "MainWindow.h"
int main(int argc, char** argv){
QApplication GUI(argc, argv);
MainWindow window;
window.shou();
return GUI.exec();
}
MainWindow.cxx
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
}
MainWindow::~MainWindow()
{
}
MainWindow.hxx
#ifndef MAINWINDOW_HXX_
#define MAINWINDOW_HXX_
#include <QMainWindow>
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent =0);
~MainWindow();
};
#endif
CMakeLists.txt
cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
project(Gui_Window)
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_AUTOUIC ON)
set(CMAKE_INCLUDE_CURRENT_DIR ON)
find_package(Qt6 COMPONENTS Widgets REQUIRED)
add_library(MAINWINDOW ${CMAKE_CURRENT_SOURCE_DIR}/src/MainWindow.cxx)
add_executable(Gui_Window ${CMAKE_CURRENT_SOURCE_DIR}/app/main.cxx)
target_link_libraries(Gui_Window PUBLIC Qt6::Widgets
MAINWINDOW
)
install(TARGETS Gui_Window DESTINATION ${CMAKE_CURRENT_SOURCE_DIR}/bin)
What should be the problem?

Answer 1

Your MainWindow.cxx file should be included in your CMakeLists.txt file like this:
set(PROJECT_SOURCES MainWindow.cxx)
You'd want main in there too.
As an aside, it's much easier to use Qt Creator and let it generate the CMakeLists.txt file for you.