对于右键点击事件，这里用到的是Qt::CustomContextMenu方法，本例通过右点QTableWidget，显示下拉菜单，同时获得点击的行号。
ui界面如下图： 
//customContextMenuRequested(QPoint)信号是QWidget中唯一右键菜单点击的信号，该信号发出的条件是：widget的ContextMenuPolicy必须是Qt::CustomContextMenu，此时右键点击就会发出此信号。
ui->tableWidget->setContextMenuPolicy (Qt::CustomContextMenu);
connect(ui->tableWidget,SIGNAL(customContextMenuRequested(QPoint)),this,SLOT(show_menu(QPoint)));
void Widget::show_menu(const QPoint pos)
{
//设置菜单选项
QMenu *menu = new QMenu(ui->tableWidget);
QAction *pnew = new QAction(“第一项”,ui->tableWidget);
QAction *pnew1 = new QAction(“第二项”,ui->tableWidget);
connect (pnew,SIGNAL(triggered()),this,SLOT(clickgoose()));
connect (pnew1,SIGNAL(triggered()),this,SLOT(clickmms()));
menu->addAction(pnew);
menu->addAction(pnew1);
menu->move (cursor ().pos ());
menu->show ();
//获得鼠标点击的x，y坐标点
int x = pos.x ();
int y = pos.y ();
QModelIndex index = ui->tableWidget->indexAt (QPoint(x,y));
int row = index.row ();//获得QTableWidget列表点击的行数
}