We find a serious BUG, that in multi-layer Qt widget app, signal auto connection approach will fail if two QPushButton (for example) has same object name.
Qt deigner will automaticlly avoid using same object name for two different controls. However, when a widget contains many controls is created as a child widget in mainFrame, auto connection approach will only match first control for one slot.
To slove this problem, all control names should be changed to different style.