Qt css背景半透明

Question

我如何將QFrame的背景設置爲半透明，以便我可以看到父窗口小部件（QWidget）的背景。我試過，但背景保持黑色：

QFrame {  
    margin: 10px; 
    background: #000000; 
    border: 1px solid black; 
    opacity: 0.5; 
} 

Answer 1

請嘗試......

Widget::Widget(QWidget *parent) : QWidget(parent) 
{ 
    setWindowFlags(Qt::Window | Qt::FramelessWindowHint); 

    setAttribute(Qt::WA_NoSystemBackground); 
    setAttribute(Qt::WA_TranslucentBackground); 
    setAttribute(Qt::WA_PaintOnScreen); 

    setAttribute(Qt::WA_TransparentForMouseEvents); 
} 

void Widget::paintEvent(QPaintEvent*) 
{ 
    QPainter p(this); 
    QString text = "Some foo goes here"; 
    QFontMetrics metrics(p.font()); 
    resize(metrics.size(0, text)); 
    p.drawText(rect(), Qt::AlignCenter, text); 
}