将背景颜色添加到作为子布局的布局（在另一个布局内）

Question

布局结构：

self.mainLayout = QGridLayout()
self.subLayout1 = QGridLayout()
self.subLayout2 = QVBoxLayout()
...
...
... 
self.mainLayout.addLayout(subLayout1,0,0)

我试过：

self.mainLayout = QGridLayout()
self.panel = QWidget()
self.subLayout1 = QGridLayout(self.panel) 
self.mainLayout.addLayout(subLayout1,0,0)
self.panel.setStylesheet("background-color: red;")

Error: QLayout::addChildLayout: layout "" already has a parent

这就是我设置 mainLayout 颜色的方式

self.setAutoFillBackground(True)
        p = self.palette()
        p.setColor(self.backgroundRole(), Qt.black)
        self.setPalette(p)

显示subLayout1、subLayout2等时需要在背面

我该怎么做？

编辑：添加了 MCVE（最小、完整、可验证的示例）

from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QGridLayout
from PyQt5.QtWidgets import QWidget, QVBoxLayout, QHBoxLayout
from PyQt5.QtCore import Qt


class Window(QMainWindow):

    def __init__(self, parent=None):
        super(Window, self).__init__(parent)
        self.setWindowTitle('MCVE')

        '''Window Background'''
        self.setAutoFillBackground(True)
        p = self.palette()
        p.setColor(self.backgroundRole(), Qt.darkYellow)
        self.setPalette(p)

        '''Core Layouts'''
        self.mainLayout = QGridLayout()
        self.picLayout = QHBoxLayout()
        self.redditSubs = QVBoxLayout()
        self.downloadBar = QHBoxLayout()
        self.panel = QWidget()
        self.profileInfo = QGridLayout(self.panel)

        '''Nested Layout'''
        self.mainLayout.addLayout(self.profileInfo, 0, 0)
        self.mainLayout.addLayout(self.picLayout, 0, 1)
        self.mainLayout.addLayout(self.redditSubs, 1, 0)
        self.mainLayout.addLayout(self.downloadBar, 1, 1)

        '''Widgets'''
        self.display = QLabel('QHBoxLayout()')
        self.download = QLabel('QHBoxLayout()')
        self.subs = QLabel('QVBoxLayout()')
        self.fileInfo = QLabel('QGridLayout()')

        '''AddWidgets'''
        self.picLayout.addWidget(self.display)
        self.downloadBar.addWidget(self.download)
        self.redditSubs.addWidget(self.subs)
        self.profileInfo.addWidget(self.fileInfo, 0, 0)

        '''Stylesheet'''
        self.panel.setStyleSheet("background-color: red;")

        '''Initiating  mainLayout '''
        self.window = QWidget()
        self.window.setLayout(self.mainLayout)
        self.setCentralWidget(self.window)


if __name__ == '__main__':
    app = QApplication([])
    w = Window()
    w.showNormal()
    app.exec_()

如上所说，代码错误QLayout::addChildLayout: layout "" already has a parent, 如果 Stylesheet 部分被注释掉，QGridLayout() 标签会出现在深黄色背景之上，我想要那个背景部分为红色。

Answer 1

QXLayout 不是视觉元素，而是 class 控制位置，尤其是分配的小部件的大小。因此，想要为不是视觉元素的 class 设置颜色是没有意义的。

另一方面，错误是因为以下2个代码是等价的：

x = QXLayout(w)

x = QXLayout()
w.setLayout(x)

在您的情况下，您已使用以下代码指示布局 "profileInfo" 属于 "panel"：self.profileInfo = QGridLayout(self.panel)，但随后您指示同一布局属于 "mainLayout" 通过以下代码：self.mainLayout.addLayout(self.profileInfo, 0, 0)。因此，为避免警告，您必须通过将最后一个代码替换为 self.mainLayout.addWidget(self.panel, 0, 0)。

更新：

如果您希望一个小部件位于另一个小部件内，那么它必须是第二个小部件的子项，因此 "fileInfo" 必须是 "panel" 的子项，但是既然您希望它占据父级的整个尺寸，那么你必须使用布局。

from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QGridLayout
from PyQt5.QtWidgets import QWidget, QVBoxLayout, QHBoxLayout
from PyQt5.QtCore import Qt


class Window(QMainWindow):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)
        self.setWindowTitle("MCVE")

        """Window Background"""
        self.setAutoFillBackground(True)
        p = self.palette()
        p.setColor(self.backgroundRole(), Qt.darkYellow)
        self.setPalette(p)

        """Core Layouts"""
        self.mainLayout = QGridLayout()
        self.picLayout = QHBoxLayout()
        self.redditSubs = QVBoxLayout()
        self.downloadBar = QHBoxLayout()
        self.profileInfo = QGridLayout()

        """Nested Layout"""
        self.mainLayout.addLayout(self.profileInfo, 0, 0)
        self.mainLayout.addLayout(self.picLayout, 0, 1)
        self.mainLayout.addLayout(self.redditSubs, 1, 0)
        self.mainLayout.addLayout(self.downloadBar, 1, 1)

        """Widgets"""
        self.display = QLabel("QHBoxLayout()")
        self.download = QLabel("QHBoxLayout()")
        self.subs = QLabel("QVBoxLayout()")

        self.fileInfo = QLabel("QGridLayout()")

        self.panel = QWidget()

        """AddWidgets"""
        self.picLayout.addWidget(self.display)
        self.downloadBar.addWidget(self.download)
        self.redditSubs.addWidget(self.subs)
        self.profileInfo.addWidget(self.panel, 0, 0)

        lay = QVBoxLayout(self.panel)
        lay.addWidget(self.fileInfo)

        """Stylesheet"""
        self.panel.setStyleSheet("background-color: red;")

        """Initiating  mainLayout """
        self.window = QWidget()
        self.window.setLayout(self.mainLayout)
        self.setCentralWidget(self.window)


if __name__ == "__main__":
    app = QApplication([])
    w = Window()
    w.showNormal()
    app.exec_()

将背景颜色添加到作为子布局的布局（在另一个布局内）

add background color to a layout which is a sublayout (inside another layout)

python

pyqt

pyqt5

qlayout