how to hide a program with only toolbar left?

[berlinud]

the program contains a QHBoxLayout as a CentralWidget of QMainWindow,
inside the layout is a QTableWidget.

I want to hide all the things except for the toolbar,

I used

QMainWindow->hide();

QMainWindow->hide();

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but the result is weird:

the QTableWidget inside the QMainWindow vanished,leaving the original area of QTableWidget blank(only blank,it is still there),

what code do I need to hide this blank area?

[berlinud]

make it up~