QT禁用窗口缩放和最大化

QT中mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    setWindowFlags(windowFlags()& ~Qt::WindowMaximizeButtonHint);
    setFixedSize(this->width(), this->height());
}
MainWindow::~MainWindow()
{
    delete ui;
}
void MainWindow::on_pushButton_clicked()
{
    QWidget::close();
}