实现右击QTreeWidgetItem向里添加Item

绑定treewidget的点击信号与自定义的槽，这里的点击信号是左右键都有，只想右键需要在槽函数里多一句判断

connect(ui->treeWidget, SIGNAL(itemPressed(QTreeWidgetItem*, int)),
        this, SLOT(TreeWidgetItemPressed_Slot(QTreeWidgetItem*, int)));

槽函数实现

void Widget::on_treeWidget_itemPressed(QTreeWidgetItem *item, int column)
{
    if (qApp->mouseButtons() == Qt::RightButton) // 判断是否为右键点击
    {
        if(mExitAct==mExitMenu->exec(QCursor::pos()))
        {
            QMessageBox box;
            box.setText("确定添加");
            box.setStandardButtons(QMessageBox::Ok | QMessageBox::Cancel);
            int ret = box.exec();
            QTreeWidgetItem *item;
            switch (ret)
            {
              case QMessageBox::Ok:
                  // Save was clicked
                item=new QTreeWidgetItem(