QWidget :: setLayout：试图设置QLayout＆＃34;＆＃34;在ProgramWindow＆＃34;＆＃34;，已经有一个布局

Question

import os
import sys

from PyQt5 import QtGui
from PyQt5 import QtWidgets

from PyQt5.QtGui import *
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *

def main():
    app = QtWidgets.QApplication(sys.argv)
    programWindow = ProgramWindow()

    programWindow.show()
    sys.exit(app.exec_())


class ProgramWindow(QtWidgets.QMainWindow):

    def __init__(self):
        QtWidgets.QMainWindow.__init__(self)

        self.setup_main_window()
        self.set_window_layout()

    def setup_main_window(self):
        self.resize( 800, 600  )
        self.setWindowTitle( "Test" )

    def set_window_layout(self):
        self.startSimulationButton = QPushButton( 'Start Simulation' )

        horizontalLayout = QHBoxLayout()
        horizontalLayout.addWidget( self.startSimulationButton )

        horizontalGroupBox = QGroupBox( "My Group" )
        horizontalGroupBox.setLayout( horizontalLayout )

        main_vertical_layout = QVBoxLayout()
        main_vertical_layout.addWidget( horizontalGroupBox )
        self.setLayout( main_vertical_layout )


if __name__ == "__main__":
    main()

当我运行它时，它会显示一个空窗口并在控制台上抛出此错误：

QWidget::setLayout: Attempting to set QLayout "" on ProgramWindow "", which already has a layout

我已经查看了QLayout: Attempting to add QLayout "" to QWidget "", which already has a layout，但我不认为我正在做这些，这段代码有什么问题？

注释掉最后一行self.setLayout( main_vertical_layout )修复了它，但当然，屏幕上没有显示任何内容。

此代码应使用布局QGroupBox创建QHBoxLayout，并将QGroupBox放在布局QVBoxLayout中。 QVBoxLayout应附在我的主窗口上：

1. QHBoxLayout，负责
2. QGroupBox
3. QVBoxLayout
4. ProgramWindow

Answer 1

用@Aviad说你的代码可能是这样的：

import sys

from PyQt5.QtWidgets import (QApplication, QMainWindow, QWidget, QPushButton,
                             QHBoxLayout, QGroupBox, QVBoxLayout)

class ProgramWindow(QMainWindow):
    def __init__(self):
        QMainWindow.__init__(self)

        self.setup_main_window()
        self.set_window_layout()

    def setup_main_window(self):
        self.centralwidget = QWidget()
        self.setCentralWidget(self.centralwidget)
        self.resize( 800, 600  )
        self.setWindowTitle( "Test" )

    def set_window_layout(self):
        self.startSimulationButton = QPushButton( 'Start Simulation' )

        self.horizontalLayout = QHBoxLayout(self.centralwidget) 
        self.horizontalLayout.addWidget( self.startSimulationButton )

        self.horizontalGroupBox = QGroupBox( "My Group" )
        self.horizontalLayout.addWidget( self.horizontalGroupBox )

        self.main_vertical_layout = QVBoxLayout()
        self.horizontalGroupBox.setLayout( self.main_vertical_layout )
        button1 = QPushButton( 'Button1' )
        button2 = QPushButton( 'Button2' )
        self.main_vertical_layout.addStretch(1)
        self.main_vertical_layout.addWidget( button1 )
        self.main_vertical_layout.addWidget( button2 )

def main():
    app = QApplication(sys.argv)
    programWindow = ProgramWindow()

    programWindow.show()
    sys.exit(app.exec_())

if __name__ == "__main__":
    main()

Answer 2

使用QMainWindow的正确方法是使用“centralWidget”，使用您的布局设置此中央窗口小部件，然后就可以了。 见setCentralWiget