在 Linux 中的 QT C++ 中设置 QButtons 的透明度

Question

I am using Qt Creator 4.0.2 Based on Qt 5.7.0 (GCC 4.9.1 20140922 (Red Hat 4.9.1-10), 64 bit).

I am displaying an image on my widget and placing QButtons and QLabels on top of it.

It looks something like this:

I want to make the button semi-transparent. There isn't any property for it. I tried the answer given on another thread as:

ui->button->setStyleSheet("background-color: rgba(255, 255, 255, 50);");

But it didn't work for me. I also tried setStyleSheet("background:transparent;") But it didn't work.

Please suggest a way of doing it.

Answer 1

setting the bg color to "transparent" is not enough, you need to set the "border-style: outset;" and nothing else in the main window/widget...

ui->pushButton_7->setStyleSheet("background-color: transparent; style: outset;");

then:

do:

ui->pushButton_7->setStyleSheet("background-color: #FF0011");
auto qgoEffect = new QGraphicsOpacityEffect(this);
qgoEffect->setOpacity(0.15);
ui->pushButton_7->setGraphicsEffect(qgoEffect);
ui->pushButton_7->setAutoFillBackground(true);

Answer 2

Setting a transparent background to the button is not enough: you have to set some attributes to your main widget in order to ask the window manager to let the button to manage its own background.

QWidget* w = new QWidget();

QPushButton* btn = new QPushButton("Click me", w);
btn->setStyleSheet("background-color: rgba(255, 255, 255, 50);");

w->setWindowFlags(Qt::FramelessWindowHint); // Do not display the window frame
w->setAttribute( Qt::WA_TranslucentBackground, true ); // Do not display the default background

w->show();