QMessageBox 模态框

void MainWindow::on_pushButton_clicked()
{
    QMessageBox *msgbox_ = new QMessageBox(this);
    msgbox_->setWindowTitle(tr("模态框"));
    msgbox_->setWindowModality(Qt::WindowModal); //通过这个 然后下面可以用show 实现模态框
    msgbox_->setWindowFlags(msgbox_->windowFlags() | Qt::Sheet);
    msgbox_->setStandardButtons(QMessageBox::Ok);
    msgbox_->setIcon(QMessageBox::Warning);
    msgbox_->setText("提示内容");
    msgbox_->show(); //结合上面的setWindowModality(Qt::WindowModal)
    //msgbox_->exec();//可以直接使用exec来实现模态框
}