Err msg: QMainWindow::getContentsMargins(left,top,right,bottom);

[askunix]

G:\st_git\dragWindow\dragWinDemo\Qt-Nice-Frameless-Window\framelesswindow\framelesswindow.cpp:270: error: C2039: "getContentsMargins": 不是 "QMainWindow" 的成员 F:\QT_6.2\6.2.3\msvc2019_64\include\QtWidgets\qmainwindow.h(60): note: 参见“QMainWindow”的声明

[makerinchina-iot]

    *left = QMainWindow::contentsMargins().left();
    *top = QMainWindow::contentsMargins().top();
    *right = QMainWindow::contentsMargins().right();
    *bottom = QMainWindow::contentsMargins().bottom();