About FramelessWindowHint and winId

[Wong]

It's OK now!

MainWindow::MainWindow(QWidget* parent):
    QMainWindow(parent)
{
...
    this->setWindowFlags(Qt::WindowMinimizeButtonHint | Qt::FramelessWindowHint);
    this->setAttribute(Qt::WA_TranslucentBackground, false); //< Can't set translucentBackground true
    m_hwnd = this->viewPage->winId();
...
}

MainWindow::MainWindow(QWidget* parent):
    QMainWindow(parent)
{
...
    this->setWindowFlags(Qt::WindowMinimizeButtonHint | Qt::FramelessWindowHint);
    this->setAttribute(Qt::WA_TranslucentBackground, false); //< Can't set translucentBackground true
    m_hwnd = this->viewPage->winId();
...
}

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Although play properly, but I want set QMainWindow's style sheet (border-radius:8px).
How should I do？