const T & at ( int i ) const
----------------------------------
实际代码如下:
QList< QStringList > m_showlist;
QStringList sss1,sss2;
sss1 << "111" << "222";
sss2 << "333" << "444";
m_showlist.push_back(sss1);
m_showlist.push_back(sss2);
for (int i=0; i<m_showlist.count(); i++) {
QStringList sss = m_showlist.at(i);
qDebug() << " old : " << sss;
sss[1] = "jjj"; // 这里,修改无效,这是怎么回事???
qDebug() << " new : " << m_showlist.at(i);
}
for (int i=0; i<m_showlist.count(); i++) {
qDebug() << " old : " << m_showlist.at(i);
m_showlist[1] = "jjj"; // 修改有效
qDebug() << " new : " << m_showlist.at(i);
}