Qt标准对话框之消息对话框(QMessageBox)

public slots:
void question();
void information();
void warning();
void critical();
void about();

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
resize(600,600);
QPushButton *btn1 = new QPushButton(tr("问题对话框"),this);
QPushButton *btn2 = new QPushButton(tr("提示对话框"),this);
QPushButton *btn3 = new QPushButton(tr("警告对话框"),this);
QPushButton *btn4 = new QPushButton(tr("错误对话框"),this);
QPushButton *btn5 = new QPushButton(tr("关于对话框"),this);
btn1->move(50,50);
btn2->move(170,50);
btn3->move(50,100);
btn4->move(170,100);
btn5->move(50,150);
connect(btn1,&QPushButton::clicked,this,&MainWindow::question);
connect(btn2,&QPushButton::clicked,this,&MainWindow::information);
connect(btn3,&QPushButton::clicked,this,&MainWindow::warning);
connect(btn4,&QPushButton::clicked,this,&MainWindow::critical);
connect(btn5,&QPushButton::clicked,this,&MainWindow::about);
}

void MainWindow::question()
{
int ret = QMessageBox::question(this,tr("退出"),tr("你确定要要退出吗?"),QMessageBox::Yes,QMessageBox::No);
if(ret == QMessageBox::Yes)
close();
}

void MainWindow::information()
{
QMessageBox::information(this,tr("消息"),tr("今天是5.21"),QMessageBox::Ok);
}

void MainWindow::warning()
{
QMessageBox::warning(this,tr("警告"),tr("可是你没女朋友"),QMessageBox::Abort);
}

void MainWindow::critical()
{
QMessageBox::critical(this,tr("错误"),tr("错会对的"),QMessageBox::YesAll);
}

void MainWindow::about()
{
QMessageBox::about(this,tr("关于"),tr("我是Marco"));
}