How to switch TranslucentBackground ?

sonichy

setAttribute(Qt::WA_TranslucentBackground, true) can change normal background to translucent, but can not change translucent to normal.
close() then open(), update() are helpless too.

void MainWindow::changeBackground(bool on){
qDebug() << on;
setAttribute(Qt::WA_TranslucentBackground,on);
}

QAction *backgroundAction;
backgroundAction=new QAction("背景透明",traymenu);
backgroundAction->setCheckable(true);
connect(backgroundAction, SIGNAL(toggled(bool)),this, SLOT(changeBackground(bool)));

Devopia53

@sonichy

If it is possible to change from a normal state to a translucent state, like this:

[...]
setAttribute(Qt::WA_TranslucentBackground, on);
if (on) {
    setWindowFlags(windowFlags() | Qt::FramelessWindowHint); // if MS Windows
}
else {
    setWindowFlags(windowFlags() ^ Qt::FramelessWindowHint); // if MS Windows
    setAttribute(Qt::WA_NoSystemBackground, on);
}
show();
[...]