void BMFilterCase::clear()
{
    bmDebug("BMFilterCase::clear");
    QList<BMFilterAbstract *> filters = findChildren<BMFilterAbstract *>();
    while(filters.count() != 0)
    {
        children().first()->setParent(NULL);
    }
}
这样的代码,能否在BMFilterCase中去掉所有基类为BMFilterAbstract的子对象?