如何删除对已关闭窗口的所有引用？

Question

在下面的示例中，我从主窗口打开新的子窗口。对于每个新窗口，我在列表中添加对它的引用以跟踪所有新窗口（我的整个软件中有很多）。 我的问题是，当我打开了几个窗口并关闭了其中一些窗口时，对这些关闭窗口的引用仍然出现在列表中：

1 window open
[<__main__.window object at 0x000002B91B7D1798>]
2 windows open
[<__main__.window object at 0x000002B91B7D1798>, <__main__.window object at 0x000002B91B7D19D8>]
3 windows open    
[<__main__.window object at 0x000002B91B7D1798>, <__main__.window object at 0x000002B91B7D19D8>, <__main__.window object at 0x000002B91B7D1C18>]
4 windows open
[<__main__.window object at 0x000002B91B7D1798>, <__main__.window object at 0x000002B91B7D19D8>, <__main__.window object at 0x000002B91B7D1C18>, <__main__.window object at 0x000002B91B7D1E58>]

hereI closed the first two windows, so 3 windows are opened, but I still have :
[<__main__.window object at 0x000002B91B7D1798>, <__main__.window object at 0x000002B91B7D19D8>, <__main__.window object at 0x000002B91B7D1C18>, <__main__.window object at 0x000002B91B7D1E58>, <__main__.window object at 0x000002B91B8640D8>]

我怎样才能真正关闭子窗口并且在我的列表中没有它们的引用？否则，它们显然不会关闭。

这里是 MRE

from PyQt5.QtWidgets import *
import sys



class window(QMainWindow):
    def __init__(self, parent=None ):
        super(window, self).__init__()
        self.centralWidget = QWidget()
        self.setCentralWidget(self.centralWidget)
        self.HBOX = QVBoxLayout()
        self.PB = QPushButton('open new window')
        self.PB.clicked.connect(self.new_window)
        self.HBOX.addWidget(self.PB)
        self.centralWidget.setLayout(self.HBOX)

        self.windows_list = []

    def new_window(self):
        self.windows_list.append(window(self))
        self.windows_list[-1].show()
        print(self.windows_list)

 
if __name__ == "__main__":

    app = QApplication(sys.argv)
    ex = window()
    ex.show()
    sys.exit(app.exec_())

Answer 1

请记住，关闭窗口不会将其删除（除非设置了Qt.WA_DeleteOnClose 属性，默认情况下不设置）。

一种可能的解决方案是覆盖closeEvent 并发送自定义信号。

class Window(QMainWindow):
    closed = QtCore.pyqtSignal(object)
    # ...
    def new_window(self):
        new_window = Window(self)
        self.windows_list.append(new_window)
        new_window.show()
        new_window.closed.connect(self.window_list.remove)

    def closeEvent(self, event):
        self.closed.emit(self)

另一种可能性是始终设置 Qt.WA_DeleteOnClose 属性并连接到 destroyed 信号，但在这种情况下，您不能依赖信号参数（它与实际删除的不匹配window)，而必须使用带有窗口实例的 lambda：

class Window(QMainWindow):
    # ...
    def new_window(self):
        new_window = Window(self)
        self.windows_list.append(new_window)
        new_window.setAttribute(Qt.WA_DeleteOnClose)
        new_window.show()
        new_window.destroyed.connect(lambda: self.windows_list.remove(new_window))

_{请注意，我将类名大写，因为类不应使用小写的名称。}

Answer 2

您可以使用closeEvent 发送信号：

import sys

from PyQt5.QtCore import pyqtSlot, pyqtSignal
from PyQt5.QtWidgets import (
    QMainWindow, QApplication, QPushButton, QVBoxLayout, QWidget
)
from PyQt5.QtGui import QCloseEvent


class window(QMainWindow):
    closed = pyqtSignal(QMainWindow)

    def __init__(self, parent=None):
        super(window, self).__init__()
        self.centralWidget = QWidget()
        self.setCentralWidget(self.centralWidget)
        self.HBOX = QVBoxLayout()
        self.PB = QPushButton('open new window')
        self.PB.clicked.connect(self.new_window)
        self.HBOX.addWidget(self.PB)
        self.centralWidget.setLayout(self.HBOX)

        self.windows_list = []

    def new_window(self):
        new_window = window(self)
        new_window.closed.connect(self.remove_window_from_list)
        self.windows_list.append(new_window)
        self.windows_list[-1].show()
        print(self.windows_list)

    @pyqtSlot(QMainWindow)
    def remove_window_from_list(self, window: QMainWindow) -> None:
        self.windows_list.remove(window)
        print(self.windows_list)

    @pyqtSlot(QCloseEvent)
    def closeEvent(self, a0: QCloseEvent) -> None:
        self.closed.emit(self)
        super().closeEvent(a0)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    ex = window()
    ex.show()
    sys.exit(app.exec_())