qt - 如何删除小部件上已经存在的布局？

Question

You must first delete the existing layout manager (returned by layout()) before you can call setLayout() with the new layout.

来自 http://doc.qt.io/qt-5.9/qwidget.html#setLayout

哪个函数用于删除以前的布局？

Answer 1

克里斯威尔逊的回答是正确的，但我发现布局不会删除它下面的子布局和 qwidgets。如果您有复杂的布局或可能有内存泄漏，最好手动进行。

QLayout * layout = new QWhateverLayout();

// ... create complicated layout ...

// completely delete layout and sublayouts
QLayoutItem * item;
QLayout * sublayout;
QWidget * widget;
while ((item = layout->takeAt(0))) {
    if ((sublayout = item->layout()) != 0) {/* do the same for sublayout*/}
    else if ((widget = item->widget()) != 0) {widget->hide(); delete widget;}
    else {delete item;}
}

// then finally
delete layout;