在Mac OS上使用Visual Studio Code创建C++ Qt的Hello World应用

引言

Qt是一个跨平台的应用程序和用户界面框架，而Visual Studio Code是一个功能强大的编辑器，两者结合可以极大地提升开发效率。本文将指导你在Mac OS上使用Visual Studio Code创建一个简单的Qt 'Hello World'窗口应用。

环境准备

确保你的MacBook OS运行最新的操作系统。
安装Homebrew，Mac OS的包管理器。
通过Homebrew安装Qt：brew install qt。
安装Visual Studio Code。
在Visual Studio Code中安装C++扩展。

创建Qt项目

1、使用Qt的qmake工具创建项目：

bash 复制代码

qmake -project "QT += widgets" -o .project
qmake

2、创建mainwindow.h和mainwindow.cpp文件，实现窗口和主函数。

编写代码

mainwindow.h定义了窗口类。

bash 复制代码

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
};

#endif // MAINWINDOW_H

mainwindow.cpp实现了窗口的构造和析构。

bash 复制代码

#include "mainwindow.h"
#include <QApplication>
#include <QLabel>

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
{
    setWindowTitle("Hello World");
    QLabel *label = new QLabel("Hello World", this);
    label->setGeometry(50, 50, 200, 50); // 位置和大小可以根据需要调整
}

MainWindow::~MainWindow()
{
    // 析构函数
}

main.cpp是程序的入口点，创建并显示MainWindow。

bash 复制代码

#include <QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    MainWindow mainWindow;
    mainWindow.show();

    return app.exec();
}

构建项目

确保.pro文件正确配置了项目设置和文件列表。

bash 复制代码

QT       += core gui widgets

TARGET = hello
TEMPLATE = app

SOURCES += main.cpp \
           mainwindow.cpp

HEADERS += mainwindow.h

使用qmake生成Makefile：
bash 复制代码
```
qmake project.pro
```
使用make命令构建项目：
bash 复制代码
```
make
```

运行应用

运行生成的可执行文件：

bash 复制代码

./hello.app/Contents/MacOS/hello

复制代码

错误处理

如果在构建或运行过程中遇到问题，请检查：

所有文件是否在正确的位置。
.pro文件是否包含了所有必要的源文件和头文件。
Qt和编译器的版本是否兼容。

总结

通过本文，你学会了如何在Mac OS上使用Visual Studio Code和Qt创建一个基本的'Hello World'窗口应用。这只是一个开始，Qt的强大功能等待着你去探索。

附加资源

bash 复制代码

douxiaobo@192 helloworld_qt % code .
douxiaobo@192 helloworld_qt % qmake -project "QT += widgets" -o .project
douxiaobo@192 helloworld_qt % qmake
Usage: qmake [mode] [options] [files]

QMake has two modes, one mode for generating project files based on
some heuristics, and the other for generating makefiles. Normally you
shouldn't need to specify a mode, as makefile generation is the default
mode for qmake, but you may use this to test qmake on an existing project

Mode:
  -project       Put qmake into project file generation mode
                 In this mode qmake interprets [files] as files to
                 be added to the .pro file. By default, all files with
                 known source extensions are added.
                 Note: The created .pro file probably will 
                 need to be edited. For example add the QT variable to 
                 specify what modules are required.
  -makefile      Put qmake into makefile generation mode (default)
                 In this mode qmake interprets files as project files to
                 be processed, if skipped qmake will try to find a project
                 file in your current working directory

Warnings Options:
  -Wnone         Turn off all warnings; specific ones may be re-enabled by
                 later -W options
  -Wall          Turn on all warnings
  -Wparser       Turn on parser warnings
  -Wlogic        Turn on logic warnings (on by default)
  -Wdeprecated   Turn on deprecation warnings (on by default)

Options:
   * You can place any variable assignment in options and it will be *
   * processed as if it was in [files]. These assignments will be    *
   * processed before [files] by default.                            *
  -o file        Write output to file
  -d             Increase debug level
  -t templ       Overrides TEMPLATE as templ
  -tp prefix     Overrides TEMPLATE so that prefix is prefixed into the value
  -help          This help
  -v             Version information
  -early         All subsequent variable assignments will be
                 parsed right before default_pre.prf
  -before        All subsequent variable assignments will be
                 parsed right before [files] (the default)
  -after         All subsequent variable assignments will be
                 parsed after [files]
  -late          All subsequent variable assignments will be
                 parsed right after default_post.prf
  -norecursive   Don't do a recursive search
  -recursive     Do a recursive search
  -set <prop> <value> Set persistent property
  -unset <prop>  Unset persistent property
  -query <prop>  Query persistent property. Show all if <prop> is empty.
  -qtconf file   Use file instead of looking for qt6.conf, then qt.conf
  -cache file    Use file as cache           [makefile mode only]
  -spec spec     Use spec as QMAKESPEC       [makefile mode only]
  -nocache       Don't use a cache file      [makefile mode only]
  -nodepend      Don't generate dependencies [makefile mode only]
  -nomoc         Don't generate moc targets  [makefile mode only]
  -nopwd         Don't look for files in pwd [project mode only]
douxiaobo@192 helloworld_qt % make
make: *** No targets specified and no makefile found.  Stop.
douxiaobo@192 helloworld_qt % make project.pro
make: Nothing to be done for `project.pro'.
douxiaobo@192 helloworld_qt % qmake project.pro
Info: creating stash file /Users/douxiaobo/Documents/Practice in Coding/C++/helloworld_qt/.qmake.stash
WARNING: Failure to find: mainwindow.h
douxiaobo@192 helloworld_qt % qmake project.pro
WARNING: Failure to find: mainwindow.h
douxiaobo@192 helloworld_qt % qmake project.pro
douxiaobo@192 helloworld_qt % make
/Library/Developer/CommandLineTools/usr/bin/clang++ -c -pipe -stdlib=libc++ -O2 -std=gnu++1z  -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=14.0 -Wall -Wextra -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I. -I/opt/homebrew/lib/QtWidgets.framework/Headers -I/opt/homebrew/lib/QtGui.framework/Headers -I/opt/homebrew/lib/QtCore.framework/Headers -I. -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/opt/homebrew/share/qt/mkspecs/macx-clang -F/opt/homebrew/lib -o main.o main.cpp
/Library/Developer/CommandLineTools/usr/bin/clang++ -c -pipe -stdlib=libc++ -O2 -std=gnu++1z  -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=14.0 -Wall -Wextra -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I. -I/opt/homebrew/lib/QtWidgets.framework/Headers -I/opt/homebrew/lib/QtGui.framework/Headers -I/opt/homebrew/lib/QtCore.framework/Headers -I. -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/opt/homebrew/share/qt/mkspecs/macx-clang -F/opt/homebrew/lib -o mainwindow.o mainwindow.cpp
/Library/Developer/CommandLineTools/usr/bin/clang++ -pipe -stdlib=libc++ -O2 -std=gnu++1z  -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=14.0 -Wall -Wextra -dM -E -o moc_predefs.h /opt/homebrew/share/qt/mkspecs/features/data/dummy.cpp
/opt/homebrew/share/qt/libexec/moc -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB --include '/Users/douxiaobo/Documents/Practice in Coding/C++/helloworld_qt/moc_predefs.h' -I/opt/homebrew/share/qt/mkspecs/macx-clang -I'/Users/douxiaobo/Documents/Practice in Coding/C++/helloworld_qt' -I/opt/homebrew/lib/QtWidgets.framework/Headers -I/opt/homebrew/lib/QtGui.framework/Headers -I/opt/homebrew/lib/QtCore.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1 -I/Library/Developer/CommandLineTools/usr/lib/clang/15.0.0/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include -I/Library/Developer/CommandLineTools/usr/include -F/opt/homebrew/lib mainwindow.h -o moc_mainwindow.cpp
/Library/Developer/CommandLineTools/usr/bin/clang++ -c -pipe -stdlib=libc++ -O2 -std=gnu++1z  -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=14.0 -Wall -Wextra -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I. -I/opt/homebrew/lib/QtWidgets.framework/Headers -I/opt/homebrew/lib/QtGui.framework/Headers -I/opt/homebrew/lib/QtCore.framework/Headers -I. -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/opt/homebrew/share/qt/mkspecs/macx-clang -F/opt/homebrew/lib -o moc_mainwindow.o moc_mainwindow.cpp
/Library/Developer/CommandLineTools/usr/bin/clang++ -stdlib=libc++ -headerpad_max_install_names  -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=14.0 -Wl,-rpath,@executable_path/../Frameworks -Wl,-rpath,/opt/homebrew/lib -o hello.app/Contents/MacOS/hello  main.o mainwindow.o moc_mainwindow.o   -F/opt/homebrew/lib -framework QtWidgets -framework QtGui -framework AppKit -framework ImageIO -framework Metal -framework QtCore -framework IOKit -framework DiskArbitration -framework AGL -framework OpenGL   
douxiaobo@192 helloworld_qt % ./hello.app/Contents/MacOS/hello
douxiaobo@192 helloworld_qt %

project.pro

bash 复制代码

QT += widgets

SOURCES += mainwindow.cpp

mainwindow.cpp

bash 复制代码

#include <QApplication>
#include <QMainWindow>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    QMainWindow window;
    window.setWindowTitle("Hello World");
    window.show();

    return app.exec();
}

运行结果成功了。

命令行如下：

bash 复制代码

douxiaobo@192 helloworld_qt % qmake project.pro
douxiaobo@192 helloworld_qt % make
/Library/Developer/CommandLineTools/usr/bin/clang++ -c -pipe -stdlib=libc++ -O2 -std=gnu++1z  -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=14.0 -Wall -Wextra -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I. -I/opt/homebrew/lib/QtWidgets.framework/Headers -I/opt/homebrew/lib/QtGui.framework/Headers -I/opt/homebrew/lib/QtCore.framework/Headers -I. -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/AGL.framework/Headers -I/opt/homebrew/share/qt/mkspecs/macx-clang -F/opt/homebrew/lib -o mainwindow.o mainwindow.cpp
/Library/Developer/CommandLineTools/usr/bin/clang++ -stdlib=libc++ -headerpad_max_install_names  -arch arm64 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk -mmacosx-version-min=14.0 -Wl,-rpath,@executable_path/../Frameworks -Wl,-rpath,/opt/homebrew/lib -o project.app/Contents/MacOS/project  mainwindow.o   -F/opt/homebrew/lib -framework QtWidgets -framework QtGui -framework AppKit -framework ImageIO -framework Metal -framework QtCore -framework IOKit -framework DiskArbitration -framework AGL -framework OpenGL   
douxiaobo@192 helloworld_qt % ./project.app/Contents/MacOS/project
douxiaobo@192 helloworld_qt %