QT5-设置窗体透明

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    this->setWindowFlags(Qt::FramelessWindowHint);
    this->setWindowOpacity(1);
    this->setAttribute(Qt::WA_TranslucentBackground);

}