QT简单pro文件和main.cpp介绍

pro文件

#-------------------------------------------------
#
# Project created by QtCreator 2019-05-29T09:26:32
#
#-------------------------------------------------
#模块，头文件需要什么模块，在头文件按F1帮助文档查找
QT       += core gui

#高于4版本，添加QT += widgets，为了兼容Qt4
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

#应用程序的名字
TARGET = 01_QtTest

#指定makefile的类型，生成app可执行程序
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

CONFIG += c++11

#源文件 .cpp文件
SOURCES += \
        main.cpp \
        mywidget.cpp

#头文件 .h文件
HEADERS += \
        mywidget.h

# Default rules for deployment.
qnx: target.path = /tmp/$${
    
    TARGET}/bin
else: unix:!android: target.path = /opt/$${
    
    TARGET}/bin
!isEmpty(target.path): INSTALLS += target

main.cpp

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

//QApplication应用程序类
//Qt头文件没有.h
//头文件和类名一样

int main(int argc, char *argv[])
{
    
    
    //有且只有一个应用程序类的对象
    QApplication a(argc, argv);

    //MyWidget继承与QWidget,QWidget是一个窗口基类
    //所以MyWidget也是窗口类
    //w就是一个窗口
    MyWidget w;

    //窗口创建默认是隐藏的，需要人为显示
    w.show();

    //a是应用程序对象
    //让程序一直执行，等待用户操作
    //等待事件发生
    return a.exec();
}