我如何解决 axxess 的问题 "受保护的 " 目的 ？

我正在尝试识别 Qt“连接”功能的“发送者”。

这

int i = RXobject->senderSignalIndex();

似乎是完成我的任务的好方法，但是……

我得到了“受保护”成员，但不知道如何继续……

请忽略不相关的代码，这是“正在建设中”
我问的是C++问题，与Qt无关。

void   MainWindow_Bluetooth::processMenu(int index_submenu, int index_mainmenu)
{
#ifdef LAMBDA
    text = "TASK DEBUG connect... "; //connect
    text += Q_FUNC_INFO;
    text += QString::number(__LINE__);
    // move index to class !!!
    text += " main loop index_main ";
    text += QString::number(index_mainmenu);
    text += " embeded loop  index_sub ";
    text += QString::number(index_submenu);
    text += " main loop class passed index ";
    text += QString::number(index);
    qDebug() << text;
#endif
    {// analyze indexes received block
        QString text;
        QObject *RXobject = sender();
        RXobject->dumpObjectInfo();
        QObjectList children = RXobject->children();
       //; text = RXobject->children().at(0);
        //QObjectList *RXChildren = RXobject->children();
        //QObject *RXparent = RXobject->parent();
        //QObject *TEST_parent = RXparent->parent();

        // protected member ???
int i = RXobject->senderSignalIndex();


//int SenderIndex = RXobject::​senderSignalIndex();

        //text = RXobject->dumpObjectInfo();

        text = Q_FUNC_INFO;
        qDebug() << text;

/mnt/A_BT_DEC10/BT__PROGRAMS/A_JAN11/A_BT_LIBRARY/terminal_Bluetooth/mainwindow_Bluetooth_copy.cpp:3890: error: 'senderSignalIndex' is a protected member of 'QObject'
mainwindow_Bluetooth_copy.cpp:3890:19: error: 'senderSignalIndex' is a protected member of 'QObject'
int i = RXobject->senderSignalIndex();
                  ^
/home/nov25-1/Qt/5.15.2/gcc_64/include/QtCore/qobject.h:435:9: note: can only access this member on an object of type 'MainWindow_Bluetooth'
    int senderSignalIndex() const;
        ^

我尝试过的：

请 Google 女士提供“发件人