Qt加载qss文件

//在main函数中加载qss文件
QFile file(QDir::currentPath() + "/ui.qss");
if (file.open(QFile::ReadOnly))
{
    QString stylesheet = QLatin1String(file.readAll());
    qApp->setStyleSheet(stylesheet);
    file.close();
} 
else
{
    QMessageBox::warning(NULL, "warning", "openfailed",QMessageBox::Yes | QMessageBox::No,QMessageBox::Yes);
}