一、时间转换（QDateTime、QString、time_t）
1、QDateTime转换为QString
QString strBuffer;
QDateTime time;
time = QDateTime::currentDateTime();
strBuffer = time.toString("yyyy-MM-dd hh:mm:ss");
2、QString转换为QDateTime
QString strBuffer;
QDateTime time;
strBuffer = "2018-06-06 14:05:00";
time = QDateTime::fromString(strBuffer, "yyyy-MM-dd hh:mm:ss");
3、QDateTime转换为time_t
time_t curTime;
QDateTime time;
time = QDateTime::fromTime_t(curTime);
4、QDateTime转换为time_t
time_t curTime;
QDateTime time;
curTime = time.toTime_t();
二、QModelIndex和QStandardItem
1、 QModelIndex 转换成QStandardItem
QStandardItem * item=QStandardItemModel::itemFromIndex(const QModelIndex & index) const
2 、QStandardItem 转换成 QModelIndex
QModelIndex model = QStandardItem::index() const