<![CDATA[custom QLayout undeclared identifier 'margin()']]>I tried to copy the Qt code I wrote before, but I found that there is a definition missing

int heightForWidth(int width) const override
{
        int height = (width - 2 * margin()) / m_aspectRatio + 2 * margin();
        return height;
}

7bf83953-921f-4d23-8f75-a5f6e197c9b1-image.png

]]>https://forum.qt.io/topic/145793/custom-qlayout-undeclared-identifier-marginRSS for NodeThu, 05 Nov 2026 02:02:53 GMTThu, 15 Jun 2023 14:48:42 GMT60<![CDATA[Reply to custom QLayout undeclared identifier 'margin()' on Thu, 15 Jun 2023 19:17:12 GMT]]>Hi,

You are trying to use code that was done with an older version of Qt. The margin method was already obsoleted with Qt 5 and was removed with Qt 6.

You should use contentsMargins.

]]>https://forum.qt.io/post/761604https://forum.qt.io/post/761604Thu, 15 Jun 2023 19:17:12 GMT<![CDATA[Reply to custom QLayout undeclared identifier 'margin()' on Thu, 15 Jun 2023 15:00:44 GMT]]>@ZeusFa
QLayout has a heightForWidth() (from QLayoutItem) which you can override, so I guess that is the method you are showing here.

It has no margin() method anywhere, hence the code above won't compile. Maybe you wrote another class. Maybe you added a method.

]]>https://forum.qt.io/post/761563https://forum.qt.io/post/761563Thu, 15 Jun 2023 15:00:44 GMT