QWidget背景透明

Question

I have a widget in the main window, the widget has the following styles:

    background-color:#ffeeeeee;width:100%;height:100%;

It is set-up to widget layout and controls auto size to fill the geometry of the widget, but the background of the widget is always transparent. What can I do to make it opaque?

This is using Qt5.6 running on RedHat Linux 7.2

NOTE: The syntax #ffeeeeee is specific to Qt, where the first node is the alpha, then red, green and blue octets.

Answer 1

You have too many characters in your color. Change:

background-color: #ffeeeeee;

to:

background-color: #eeeeee;

If you want to use transparency, you'll have to be explicit:

background-color: rgba(...);

Answer 2

With the background-color present and set to any of the following:

    background-color:white;width:100%;height:100%;

or

    background-color:#ffffff;width:100%;height:100%;

or my original:

    background-color:#ffeeeeee;width:100%;height:100%;

The property, autoFillBackground is set to false and the background of the widget is transparent at run-time.

However removing any background-color style and leaving the style as just:

    width:100%;height:100%

The property, autoFillBackground is set to true and the widget is opaque.

As far as I can see there is no error in the styles, I believe this may be an error in Qt.

Answer 3

Have you tried using QWidget::setWindowOpacity(1) where 1 = opaque and 0 = transperant.

Also try QGraphicsOpacityEffect.The following is code for setting the 50 percent opacity for a pushbutton but It can be extended to a widget as well.

ui->setupUi(this);
QGraphicsOpacityEffect * effect = new QGraphicsOpacityEffect(ui->pushButton);
effect->setOpacity(0.5); 
ui->pushButton->setGraphicsEffect(effect);