只有addrow,我测试用一下方法
QWidget*w = new QWidget();
this->setCentralWidget(w);
QFormLayout* fl = new QFormLayout(this);
w->setLayout(fl);
QLineEdit*txt = new QLineEdit(this);
fl->addRow(tr("aaaaaaaa"),txt);
fl->removeItem(fl->itemAt(0));
delete txt;
QComboBox *drparg = new QComboBox(this);
fl->addRow(tr("bbbbbbbbbb"),drparg);
这样楞写,惯用,但是放到程序内,就不管用了,在程序内我总是删除fl->itemAt(3)