qss中，怎么表达代码里的button->setFocusPolicy(Qt:NoFocus)

QPushButton{    color : red;    policy : nofocus; /*如何表达无焦点？*/}

#include <QtGui/QApplication>#include "mainwindow.h"//the following three header files are used for suppporting setSkin function#include <QFile>#include <QStyleFactory>#include <QTextStream>bool setSkin(QApplication* const app, QString const &skinFile);int main(int argc, char *argv[]){    QApplication a(argc, argv);    MainWindow w;    w.show();    //load qss file for skin    setSkin(&a ,"skin.qss");    return a.exec();}bool setSkin(QApplication* const app, QString const &skinFile){    QFile file(skinFile);    if (QFile::exists(skinFile) && file.open(QIODevice::ReadOnly))    {        QApplication::setStyle(QStyleFactory::create("Windows"));        QString strTemp;        QTextStream in(&file);        while (!in.atEnd())        {            strTemp.append(in.readLine());        }        file.close();        app->setStyleSheet(strTemp);    }    else    {#ifdef Q_WS_MAC        qDebug("%s: %s: File does not exist %s... setting mac style...",               __FILE__, __FUNCTION__, qPrintable(skinFile));        app->setStyle(new QMacStyle());        return true;#else        qDebug("%s: %s: File does not exist or failed to open %s",               __FILE__, __FUNCTION__, qPrintable(skinFile));        return false;#endif    }    return true;}