一.运行结果(GIF动图)：
二.附代码
day16.pro
QT += core guigreaterThan(QT_MAJOR_VERSION, 4): QT += widgetsCONFIG += c++11# The following define makes your compiler emit warnings if you use# any Qt feature that has been marked 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 it uses 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 6.0.0SOURCES += \main.cpp \widget.cppHEADERS += \widget.h# Default rules for deployment.qnx: target.path = /tmp/$${TARGET}/binelse: unix:!android: target.path = /opt/$${TARGET}/bin!isEmpty(target.path): INSTALLS += target
widget.h
#ifndef WIDGET_H#define WIDGET_H#include <QWidget>class Widget : public QWidget{Q_OBJECTpublic:Widget(QWidget *parent = nullptr);~Widget();public slots:void showWarning();void showInformation();void showQuestion();};#endif // WIDGET_H
widget.cpp
#include "widget.h"#include<QHBoxLayout>#include<QPushButton>#include<QMessageBox>#include<QDebug>Widget::Widget(QWidget *parent): QWidget(parent){QHBoxLayout* hBox=new QHBoxLayout(this);QPushButton* pb0=new QPushButton("warning");QPushButton* pb1=new QPushButton("information");QPushButton* pb2=new QPushButton("question");hBox->addWidget(pb0);hBox->addWidget(pb1);hBox->addWidget(pb2);connect(pb0,SIGNAL(clicked()),this,SLOT(showWarning()));connect(pb1,SIGNAL(clicked()),this,SLOT(showInformation()));connect(pb2,SIGNAL(clicked()),this,SLOT(showQuestion()));}void Widget::showWarning(){int sb=QMessageBox::warning(this,"warning","unuse var",QMessageBox::Open|QMessageBox::Save);qDebug()<<sb<<endl;}void Widget::showInformation(){int sb=QMessageBox::information(this,"information","unuse var",QMessageBox::Open|QMessageBox::Save);qDebug()<<sb<<endl;}void Widget::showQuestion(){int sb=QMessageBox::question(this,"question","unuse var",QMessageBox::Open|QMessageBox::Save);qDebug()<<sb<<endl;}Widget::~Widget(){}
main.cpp
#include "widget.h"#include <QApplication>int main(int argc, char *argv[]){QApplication a(argc, argv);Widget w;w.show();return a.exec();}
