CSS won't work after intallEventFilter()

[MorrisLiang]

This is how it looks like,if I comment out the code:

ui.myText->installEventFilter(this);

ui.myText->installEventFilter(this);

To copy to clipboard, switch view to plain text mode 

This is how it looks like,if I install the event filter:


and the implenmentation of evetFilter is just:

bool MyWindow::eventFilter(QObject* target,QEvent* event){return true;}

bool MyWindow::eventFilter(QObject* target,QEvent* event){return true;}

To copy to clipboard, switch view to plain text mode 

It's not just QTextEdit,I also test the other QWidget.All behaves the same:if I install eventfilter,then it's stylesheet is gone.

I apply the style sheet by calling:

QFile stylesheet("myCSS.css");
stylesheet.open(QFile::ReadOnly);
qApp->setStyleSheet(stylesheet.readAll());
stylesheet.close();

QFile stylesheet("myCSS.css");
stylesheet.open(QFile::ReadOnly);
qApp->setStyleSheet(stylesheet.readAll());
stylesheet.close();

To copy to clipboard, switch view to plain text mode 

And I also set the stylesheet directly in the qt desiner,instead loading external file.
The problem still happens.

So,anyone has come cross this weird thing?Any solution?