如何使用QSettings从子QDialog中保存LineEdit值？

Question

我有一个简单的QMainWindow，其中包含一个按钮，点击该按钮时会弹出一个子QDialog。在这个子对话框中，只有一个QLineEdit。

我想使用QLineEdit在INI file上保存此QSettings的值：

import sys
from PyQt5 import QtWidgets, QtCore
from PyQt5.QtCore import QSettings
from PyQt5.QtWidgets import QDialog, QMainWindow

from wintest import Ui_MainWindow
from test import Ui_Test

class TestDialog(QDialog, Ui_Test):

    def __init__(self, parent):
        QDialog.__init__(self, parent)
        self.setupUi(self)
        self.pushButton_save.clicked.connect(self.close)

    def saveSettings(self):
        settings = QSettings("settings.ini", QSettings.IniFormat)
        settings.setValue('key/value', self.lineEdit_test.text())

    def closeEvent(self, event):
        print('closing, saving settings...')
        self.saveSettings() # value are not saved
        event.accept()

# main UI
class WinMain(QMainWindow, Ui_MainWindow):

    settings = QSettings()

    def __init__(self, dialog):
        QMainWindow.__init__(self)
        self.setupUi(dialog)
        self.pushButton_openTestDialog.clicked.connect(self.showTestDialog)

    def showTestDialog(self):
        dialog = TestDialog(self)
        dialog.ui = Ui_Test()
        dialog.ui.setupUi(dialog)
        ok = dialog.exec_()
        dialog.show()


# main()
if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    app.addLibraryPath('.')
    window = QtWidgets.QMainWindow()

    pid = WinMain(window)

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

永远不会保存lineEdit_test的值...我在INI file的结果是：

[key]
value=

修改：包含.ui文件

TestDialog

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'test.ui'
#
# Created by: PyQt5 UI code generator 5.6
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_Test(object):
    def setupUi(self, Test):
        Test.setObjectName("Test")
        Test.resize(349, 160)
        self.label = QtWidgets.QLabel(Test)
        self.label.setGeometry(QtCore.QRect(30, 50, 71, 16))
        self.label.setObjectName("label")
        self.pushButton_save = QtWidgets.QPushButton(Test)
        self.pushButton_save.setGeometry(QtCore.QRect(140, 110, 75, 23))
        self.pushButton_save.setObjectName("pushButton_save")
        self.lineEdit_test = QtWidgets.QLineEdit(Test)
        self.lineEdit_test.setGeometry(QtCore.QRect(110, 50, 161, 20))
        self.lineEdit_test.setObjectName("lineEdit_test")

        self.retranslateUi(Test)
        QtCore.QMetaObject.connectSlotsByName(Test)

    def retranslateUi(self, Test):
        _translate = QtCore.QCoreApplication.translate
        Test.setWindowTitle(_translate("Test", "Dialog"))
        self.label.setText(_translate("Test", "MyLineEdit"))
        self.pushButton_save.setText(_translate("Test", "save settings"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Test = QtWidgets.QDialog()
    ui = Ui_Test()
    ui.setupUi(Test)
    Test.show()
    sys.exit(app.exec_())

主窗口

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'wintest.ui'
#
# Created by: PyQt5 UI code generator 5.6
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(480, 298)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.pushButton_openTestDialog = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton_openTestDialog.setGeometry(QtCore.QRect(200, 120, 75, 23))
        self.pushButton_openTestDialog.setObjectName("pushButton_openTestDialog")
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.pushButton_openTestDialog.setText(_translate("MainWindow", "PushButton"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())