9、消息对话框、文件对话框

新建项目，基类选择QMainWindow，取消勾选ui

  

mainwindow.cpp代码：

#include "mainwindow.h"
//头文件中引入
//#include <QMainWindow>
//#include<QMenuBar>
//#include<QMenu>
//#include<QMessageBox> //消息对话框
//#include<QDebug>
//#include<QFileDialog> //文件对话框

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    resize(400,200);
    QMenuBar *mBar=menuBar();//菜单栏
    QMenu *menu=mBar->addMenu("对话框");//菜单
    QMenu *m1=menu->addMenu("消息对话框");
    QAction *p11=m1->addAction("about对话框");//菜单项
    QAction *p12=m1->addAction("question对话框");
    QAction *p2=menu->addAction("文件对话框");
    connect(p11,&QAction::triggered,
            [=](){
        QMessageBox::about(this,"about标题","about对话框的内容");
    });
    connect(p12,&QAction::triggered,
            [=](){//自己指定按钮
        int result=QMessageBox::question(this,"question标题","内容：你还好吗？",QMessageBox::Yes|QMessageBox::No);
        switch (result) {
        case QMessageBox::Yes:
            qDebug()<<"我很好";
            break;
        case QMessageBox::No:
            qDebug()<<"不好";
            break;
        default:
            break;
        }
    });
    connect(p2,&QAction::triggered,
            [=](){
        //文件对话框//
        QString fileName=QFileDialog::getOpenFileName(this,"打开","/home","Image(*.jpg *.png);;Text(*.txt);;all(*.*)");
        qDebug()<<fileName;
    });

}

MainWindow::~MainWindow()
{

}