Qt 概述

1. 概念

Qt 是一个跨平台的 C++ 图形用户界面应用程序框架

常见的 C++ GUI: Qt 和 MFC

2. 跨平台

• Windows

• Linux

• MacOS

• 嵌入式平台

3. 版本

包括商业版和开源免费版

4. 案例

• Linux 桌面环境 KDE

• WPS Office

Qt 安装

下载地址:

• https://download.qt.io/archive/qt/

• https://www.qt.io/download-open-source

构建 Qt 项目

参考: https://doc.qt.io/qt-5/cmake-get-started.html

新建一个目录 Begin, 在该目录下新建 CMakeLists.txt, main.cpp 以及 build 空目录

Begin/
├── build
├── CMakeLists.txt
└── main.cpp

1 directory, 2 files

• CMakeLists.txt 的内容:

cmake_minimum_required(VERSION 3.10)

project(Begin)

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_AUTOUIC ON)
set(CMAKE_PREFIX_PATH /opt/Qt/5.15.2/gcc_64/lib/cmake)

find_package(Qt5 COMPONENTS Widgets REQUIRED)

add_executable(00-Demo main.cpp)
target_link_libraries(00-Demo Qt5::Widgets)

Qt 5.15 以后的版本, 模块库也可以写为 Qt::Widgets, 以便兼容 Qt6

• main.cpp 的内容:

#include <QApplication>
#include <QWidget>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);
    QWidget window;
    window.resize(320, 240);
    window.show();
    return app.exec();  // 主事件循环
}

编译 Qt 项目

进入 Begin/build 目录

$ cd Begin/build/
$ cmake .. && make
-- The C compiler identification is GNU 9.4.0
-- The CXX compiler identification is GNU 9.4.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/jianghuixin/CLion/Qt5/Begin/build
[ 25%] Automatic MOC and UIC for target 00-Demo
[ 25%] Built target 00-Demo_autogen
[ 50%] Building CXX object CMakeFiles/00-Demo.dir/00-Demo_autogen/mocs_compilation.cpp.o
[ 75%] Building CXX object CMakeFiles/00-Demo.dir/main.cpp.o
[100%] Linking CXX executable 00-Demo
[100%] Built target 00-Demo

在 build 目录生成了 00-Demo 可执行程序, 直接运行

$ ./00-Demo