首先我们看下QTableWidget正序创建Item
ui->charttable->setColumnCount(10);
ui->charttable->setSelectionBehavior(QAbstractItemView::SelectRows);
ui->charttable->setSelectionMode(QTableWidget::SingleSelection);
ui->charttable->setEditTriggers(QAbstractItemView::NoEditTriggers);
ui->charttable->setFocusPolicy(Qt::NoFocus);
ui->charttable->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
ui->charttable->setHorizontalHeaderLabels(QStringList()<<"编号"<<"名字"<<"年龄";
ui->charttable->setRowCount(10);
for (int i = 0; i < 10 i++)
{
QTableWidgetItem* item1 = new QTableWidgetItem(QString::number(i));
QTableWidgetItem* item2 = new QTableWidgetItem("name:"+QString::number(i));
QTableWidgetItem* item3 = new QTableWidgetItem("age:"+QString::number(i));
item1->setTextAlignment(Qt::AlignCenter);
item2->setTextAlignment(Qt::AlignCenter);
item3->setTextAlignment(Qt::AlignCenter);
ui->charttable->setItem(i,0,item1);
ui->charttable->setItem(i,1,item2);
ui->charttable->setItem(i,2,item3);
}
ui->charttable->setShowGrid(false);
正序插入2行:
ui->charttable->setRowCount(ui->charttable->rowCount()+2);
for (int i = ui->charttable->rowCount(); i < ui->charttable->rowCount()+2; i++)
{
QTableWidgetItem* item1 = new QTableWidgetItem(QString::number(i));
QTableWidgetItem* item2 = new QTableWidgetItem("name:"+QString::number(i));
QTableWidgetItem* item3 = new QTableWidgetItem("age:"+QString::number(i));
item1->setTextAlignment(Qt::AlignCenter);
item2->setTextAlignment(Qt::AlignCenter);
item3->setTextAlignment(Qt::AlignCenter);
ui->charttable->setItem(0,0,item1);
ui->charttable->setItem(0,1,item2);
ui->charttable->setItem(0,2,item3);
}
逆序插入2行:
for (int i = ui->charttable->rowCount(); i < ui->charttable->rowCount()+2; i++)
{
ui->charttable->insertRow(0); //从第一行插入
QTableWidgetItem* item1 = new QTableWidgetItem(QString::number(0));
QTableWidgetItem* item2 = new QTableWidgetItem("name:"+QString::number(i));
QTableWidgetItem* item3 = new QTableWidgetItem("age:"+QString::number(i));
item1->setTextAlignment(Qt::AlignCenter);
item2->setTextAlignment(Qt::AlignCenter);
item3->setTextAlignment(Qt::AlignCenter);
ui->charttable->setItem(0,0,item1);
ui->charttable->setItem(0,1,item2);
ui->charttable->setItem(0,2,item3);
}
//更新编号
for (int i = 0; i < ui->charttable->rowCount(); i++)
{
ui->charttable->item(i,0)->setText(QString::number(i));
}
逆序插入删除选中行。
ui->charttable->removeRow(ui->charttable->currentRow());
//更新编号
for (int i = 0; i < ui->charttable->rowCount(); i++)
{
ui->charttable->item(i,0)->setText(QString::number(i));
}
通过以上的例子,是不是发现了正序和逆序它们操作方式不一样。正序是通过setRowCount来增加行的,逆序是通过insertRow来增加行的。但是逆序还需要更新编号和反向取数据。
当然我们正序的时候也可以用insertRow来实现,所以它跟setRowCount有什么区别,经过实际测试,我发现当数据量较大时,insertRow比setRowCount快很多,当然想想它的源码逻辑也能猜测到insertRow要快很多,因为setRowCount它需要先遍历操作找到最后一条插入行,然后新增。而insertRow在指定位置新增,更新行数就可以了。