问题描述
我希望能够在我的PyQt5应用程序中保存和恢复小部件状态（属性和值）。窗口小部件状态应保存到.ini文件。以下Stackoverflow答案已经证明了这一点：
- How to save text in QLineEdits in PyQt even if the Widget gets closed?
- Loading Widgets properly while restoring from QSettings
但是，上述问题的答案并未解决我在下面的示例代码中面临的特定问题。我希望从设置.ini文件进行保存和还原对于正在运行的父窗口小部件（主窗口应用程序）的每个实例都是唯一的。因此，在保存窗口小部件属性时，所有窗口小部件的迭代都应仅发生在父窗口小部件（主窗口）的子窗口上，而不应通过全局应用程序中当前正在运行的所有窗口小部件进行。
我认为以下示例代码中的问题与for w in QtWidgets.qApp.allWidgets():行有关。我认为这一行会遍历PyQt5全局应用程序中当前打开的所有小部件。但是，当同一父窗口小部件有多个实例时，objectName中将有重复项。尽管可以在init（）期间为每个实例（例如：app_name）赋予唯一的名称，并在QSettings键中加以说明，但这可能不是最佳的通用适应性解决方案。因此，如何解决我面临的问题？如何获得settings_save()函数来遍历父窗口小部件（主窗口应用）实例的所有子窗口小部件，而不是遍历当前在全局应用程序中运行的所有父窗口小部件？在Qt docs中，找不到类似于allWidgets()的函数，该函数将允许我指定父窗口小部件（例如：QMainWindow）并提供其下的所有小部件和对象。如果可以将所有小部件都放入父小部件内，那么我可以轻松地修改函数settings_save()，不仅包括QSetting变量作为参数，还包括我要为其保存设置的小部件实例。
main_app.py
import sys
from PyQt5 import QtWidgets,uic,QtCore,QtGui
from PyQt5.QtCore import QFileInfo,QSettings,QObject
from PyQt5.QtWidgets import qApp
from ui_mainwindow import Ui_MainWindow
def settings_value_is_valid(val):
# https://stackoverflow.com/a/60028282/4988010
if isinstance(val,QtGui.Qpixmap):
return not val.isNull()
return True
def settings_restore(settings):
# https://stackoverflow.com/a/60028282/4988010
finfo = QtCore.QFileInfo(settings.fileName())
if finfo.exists() and finfo.isFile():
for w in QtWidgets.qApp.allWidgets():
if w.objectName() and not w.objectName().startswith("qt_"):
# if w.objectName():
mo = w.MetaObject()
for i in range(mo.propertyCount()):
prop = mo.property(i)
name = prop.name()
last_value = w.property(name)
key = "{}/{}".format(w.objectName(),name)
# print(prop,name,last_value,key)
if not settings.contains(key):
continue
val = settings.value(key,type=type(last_value),)
if (
val != last_value
and settings_value_is_valid(val)
and prop.isValid()
and prop.isWritable()
):
w.setProperty(name,val)
def settings_save(settings):
# https://stackoverflow.com/a/60028282/4988010
for w in QtWidgets.qApp.allWidgets():
if w.objectName() and not w.objectName().startswith("qt_"):
# if w.objectName():
mo = w.MetaObject()
for i in range(mo.propertyCount()):
prop = mo.property(i)
name = prop.name()
key = "{}/{}".format(w.objectName(),name)
val = w.property(name)
if settings_value_is_valid(val) and prop.isValid() and prop.isWritable():
settings.setValue(key,w.property(name))
class MyApp(QtWidgets.QMainWindow):
def __init__(self,app_name='DefaultAppName'):
super(MyApp,self).__init__()
self.settings = QSettings("./temp/gui_settings-{}.ini".format(app_name),QSettings.IniFormat)
self.ui = Ui_MainWindow()
self.ui.setupUi(self)
# Set window titlte and qlineedit to indicate the name of app instance
self.ui.app_instance_name.setText(app_name)
self.setwindowTitle(app_name)
# Load the saved config file saved from prevIoUs app usage
self.config_widgets_load_settings()
self.ui.action_save_current_config.triggered.connect(self.config_widgets_save_settings)
self.ui.action_load_config.triggered.connect(self.config_widgets_load_settings)
self.ui.action_clear_config_file.triggered.connect(self.config_clear_settings)
def config_widgets_save_settings(self):
# Write current state to the settings config file
settings_save(self.settings)
def config_widgets_load_settings(self):
# Load settings config file
settings_restore(self.settings)
def config_clear_settings(self):
# Clear the settings config file
self.settings.clear()
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
# First instance of the MyApp
app_one = MyApp(app_name='App#1')
app_one.show()
# Second instance of the MyApp
app_two = MyApp(app_name='App#2')
app_two.show()
app.exec_()
ui_mainwindow.py
from PyQt5 import QtCore,QtGui,QtWidgets
class Ui_MainWindow(object):
def setupUi(self,MainWindow):
MainWindow.setobjectName("MainWindow")
MainWindow.resize(330,202)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setobjectName("centralwidget")
self.gridLayoutWidget = QtWidgets.QWidget(self.centralwidget)
self.gridLayoutWidget.setGeometry(QtCore.QRect(20,80,291,51))
self.gridLayoutWidget.setobjectName("gridLayoutWidget")
self.gridLayout = QtWidgets.qgridLayout(self.gridLayoutWidget)
self.gridLayout.setContentsMargins(0,0)
self.gridLayout.setobjectName("gridLayout")
self.lineEdit1 = QtWidgets.QLineEdit(self.gridLayoutWidget)
self.lineEdit1.setobjectName("lineEdit1")
self.gridLayout.addWidget(self.lineEdit1,2,1,1)
self.pushButton1 = QtWidgets.QPushButton(self.gridLayoutWidget)
self.pushButton1.setCheckable(True)
self.pushButton1.setobjectName("pushButton1")
self.gridLayout.addWidget(self.pushButton1,1)
self.spinBox1 = QtWidgets.QSpinBox(self.gridLayoutWidget)
self.spinBox1.setMaximum(10000)
self.spinBox1.setProperty("value",37)
self.spinBox1.setobjectName("spinBox1")
self.gridLayout.addWidget(self.spinBox1,1)
self.label = QtWidgets.QLabel(self.gridLayoutWidget)
self.label.setobjectName("label")
self.gridLayout.addWidget(self.label,3)
self.horizontalLayoutWidget = QtWidgets.QWidget(self.centralwidget)
self.horizontalLayoutWidget.setGeometry(QtCore.QRect(50,20,241,31))
self.horizontalLayoutWidget.setobjectName("horizontalLayoutWidget")
self.horizontalLayout = QtWidgets.QHBoxLayout(self.horizontalLayoutWidget)
self.horizontalLayout.setContentsMargins(0,0)
self.horizontalLayout.setobjectName("horizontalLayout")
self.label_2 = QtWidgets.QLabel(self.horizontalLayoutWidget)
self.label_2.setobjectName("label_2")
self.horizontalLayout.addWidget(self.label_2)
self.app_instance_name = QtWidgets.QLineEdit(self.horizontalLayoutWidget)
self.app_instance_name.setobjectName("app_instance_name")
self.horizontalLayout.addWidget(self.app_instance_name)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0,330,21))
self.menubar.setobjectName("menubar")
self.menuFile = QtWidgets.QMenu(self.menubar)
self.menuFile.setobjectName("menuFile")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setobjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.action_save_current_config = QtWidgets.QAction(MainWindow)
self.action_save_current_config.setobjectName("action_save_current_config")
self.action_load_config = QtWidgets.QAction(MainWindow)
self.action_load_config.setobjectName("action_load_config")
self.action_clear_config_file = QtWidgets.QAction(MainWindow)
self.action_clear_config_file.setobjectName("action_clear_config_file")
self.menuFile.addAction(self.action_save_current_config)
self.menuFile.addAction(self.action_load_config)
self.menuFile.addAction(self.action_clear_config_file)
self.menubar.addAction(self.menuFile.menuAction())
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self,MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setwindowTitle(_translate("MainWindow","MainWindow"))
self.lineEdit1.setText(_translate("MainWindow","This is default text"))
self.pushButton1.setText(_translate("MainWindow","Push me"))
self.label.setText(_translate("MainWindow","My simple app with varIoUs widgets"))
self.label_2.setText(_translate("MainWindow","App instance name"))
self.menuFile.setTitle(_translate("MainWindow","File"))
self.action_save_current_config.setText(_translate("MainWindow","Save current config"))
self.action_load_config.setText(_translate("MainWindow","Load config"))
self.action_clear_config_file.setText(_translate("MainWindow","Clear config file"))
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_())
解决方法
在进一步研究Qt文档后，我找到了解决方案。每个QWidget的类型为QObject，其类型为findChildren()。此方法可用于指定要为其保存/恢复设置的父窗口小部件。
下面是创建的有助于您保存/恢复设置的方法。我的贡献是创建函数settings_get_all_widgets()。保存/恢复功能最初是由@eyllanesc创建的，我对此进行了修改，以解决该问题。
def settings_get_all_widgets(parent):
# Possible fix to the issue:
# https://stackoverflow.com/questions/64202927/how-to-save-and-restore-widget-properties-that-is-unique-for-each-instance-of-th
if parent:
# Find all children inside the given parent that is of type QWidget
all_widgets = parent.findChildren(QtWidgets.QWidget)
if parent.isWidgetType():
# If parent is of type QWidget,add the parent itself to the list
all_widgets.append(parent)
else:
# If no parent is given then get all the widgets from all the PyQt applications
all_widgets = QtWidgets.qApp.allWidgets()
return all_widgets
def settings_value_is_valid(val):
# Originally adapted from:
# https://stackoverflow.com/a/60028282/4988010
# https://github.com/eyllanesc/stackoverflow/issues/26#issuecomment-703184281
if isinstance(val,QtGui.QPixmap):
return not val.isNull()
return True
def settings_restore(settings,parent=None):
# Originally adapted from:
# https://stackoverflow.com/a/60028282/4988010
# https://github.com/eyllanesc/stackoverflow/issues/26#issuecomment-703184281
if not settings:
return
all_widgets = settings_get_all_widgets(parent)
finfo = QtCore.QFileInfo(settings.fileName())
if finfo.exists() and finfo.isFile():
for w in all_widgets:
if w.objectName() and not w.objectName().startswith("qt_"):
# if w.objectName():
mo = w.metaObject()
for i in range(mo.propertyCount()):
prop = mo.property(i)
name = prop.name()
last_value = w.property(name)
key = "{}/{}".format(w.objectName(),name)
if not settings.contains(key):
continue
val = settings.value(key,type=type(last_value),)
if (
val != last_value
and settings_value_is_valid(val)
and prop.isValid()
and prop.isWritable()
):
w.setProperty(name,val)
def settings_save(settings,parent=None):
# Originally adapted from:
# https://stackoverflow.com/a/60028282/4988010
# https://github.com/eyllanesc/stackoverflow/issues/26#issuecomment-703184281
if not settings:
return
all_widgets = settings_get_all_widgets(parent)
for w in all_widgets:
if w.objectName() and not w.objectName().startswith("qt_"):
mo = w.metaObject()
for i in range(mo.propertyCount()):
prop = mo.property(i)
name = prop.name()
key = "{}/{}".format(w.objectName(),name)
val = w.property(name)
if settings_value_is_valid(val) and prop.isValid() and prop.isWritable():
settings.setValue(key,w.property(name))
下面是自包含的工作代码，其中包含原始问题的解决方案。
import sys
from PyQt5 import QtWidgets,uic,QtCore,QtGui
from PyQt5.QtCore import QFileInfo,QSettings,QObject
from PyQt5.QtWidgets import qApp
# from ui_mainwindow import Ui_MainWindow
def settings_get_all_widgets(parent):
# Possible fix to the issue:
# https://stackoverflow.com/questions/64202927/how-to-save-and-restore-widget-properties-that-is-unique-for-each-instance-of-th
if parent:
# Find all children inside the given parent that is of type QWidget
all_widgets = parent.findChildren(QtWidgets.QWidget)
if parent.isWidgetType():
# If parent is of type QWidget,w.property(name))
class MyApp(QtWidgets.QMainWindow):
def __init__(self,app_name='DefaultAppName'):
super(MyApp,self).__init__()
self.settings = QSettings("./temp/gui_settings-{}.ini".format(app_name),QSettings.IniFormat)
self.ui = Ui_MainWindow()
self.ui.setupUi(self)
# Set window titlte and qlineedit to indicate the name of app instance
self.ui.app_instance_name.setText(app_name)
self.setWindowTitle(app_name)
# Load the saved config file saved from previous app usage
self.config_widgets_load_settings()
self.ui.action_save_current_config.triggered.connect(self.config_widgets_save_settings)
self.ui.action_load_config.triggered.connect(self.config_widgets_load_settings)
self.ui.action_clear_config_file.triggered.connect(self.config_clear_settings)
def config_widgets_save_settings(self):
# Write current state to the settings config file
settings_save(self.settings,self)
def config_widgets_load_settings(self):
# Load settings config file
settings_restore(self.settings,self)
def config_clear_settings(self):
# Clear the settings config file
self.settings.clear()
class Ui_MainWindow(object):
def setupUi(self,MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(330,202)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.gridLayoutWidget = QtWidgets.QWidget(self.centralwidget)
self.gridLayoutWidget.setGeometry(QtCore.QRect(20,80,291,51))
self.gridLayoutWidget.setObjectName("gridLayoutWidget")
self.gridLayout = QtWidgets.QGridLayout(self.gridLayoutWidget)
self.gridLayout.setContentsMargins(0,0)
self.gridLayout.setObjectName("gridLayout")
self.lineEdit1 = QtWidgets.QLineEdit(self.gridLayoutWidget)
self.lineEdit1.setObjectName("lineEdit1")
self.gridLayout.addWidget(self.lineEdit1,2,1,1)
self.pushButton1 = QtWidgets.QPushButton(self.gridLayoutWidget)
self.pushButton1.setCheckable(True)
self.pushButton1.setObjectName("pushButton1")
self.gridLayout.addWidget(self.pushButton1,1)
self.spinBox1 = QtWidgets.QSpinBox(self.gridLayoutWidget)
self.spinBox1.setMaximum(10000)
self.spinBox1.setProperty("value",37)
self.spinBox1.setObjectName("spinBox1")
self.gridLayout.addWidget(self.spinBox1,1)
self.label = QtWidgets.QLabel(self.gridLayoutWidget)
self.label.setObjectName("label")
self.gridLayout.addWidget(self.label,3)
self.horizontalLayoutWidget = QtWidgets.QWidget(self.centralwidget)
self.horizontalLayoutWidget.setGeometry(QtCore.QRect(50,20,241,31))
self.horizontalLayoutWidget.setObjectName("horizontalLayoutWidget")
self.horizontalLayout = QtWidgets.QHBoxLayout(self.horizontalLayoutWidget)
self.horizontalLayout.setContentsMargins(0,0)
self.horizontalLayout.setObjectName("horizontalLayout")
self.label_2 = QtWidgets.QLabel(self.horizontalLayoutWidget)
self.label_2.setObjectName("label_2")
self.horizontalLayout.addWidget(self.label_2)
self.app_instance_name = QtWidgets.QLineEdit(self.horizontalLayoutWidget)
self.app_instance_name.setObjectName("app_instance_name")
self.horizontalLayout.addWidget(self.app_instance_name)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0,330,21))
self.menubar.setObjectName("menubar")
self.menuFile = QtWidgets.QMenu(self.menubar)
self.menuFile.setObjectName("menuFile")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.action_save_current_config = QtWidgets.QAction(MainWindow)
self.action_save_current_config.setObjectName("action_save_current_config")
self.action_load_config = QtWidgets.QAction(MainWindow)
self.action_load_config.setObjectName("action_load_config")
self.action_clear_config_file = QtWidgets.QAction(MainWindow)
self.action_clear_config_file.setObjectName("action_clear_config_file")
self.menuFile.addAction(self.action_save_current_config)
self.menuFile.addAction(self.action_load_config)
self.menuFile.addAction(self.action_clear_config_file)
self.menubar.addAction(self.menuFile.menuAction())
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self,MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow","MainWindow"))
self.lineEdit1.setText(_translate("MainWindow","This is default text"))
self.pushButton1.setText(_translate("MainWindow","Push me"))
self.label.setText(_translate("MainWindow","My simple app with various widgets"))
self.label_2.setText(_translate("MainWindow","App instance name"))
self.menuFile.setTitle(_translate("MainWindow","File"))
self.action_save_current_config.setText(_translate("MainWindow","Save current config"))
self.action_load_config.setText(_translate("MainWindow","Load config"))
self.action_clear_config_file.setText(_translate("MainWindow","Clear config file"))
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
# First instance of the MyApp
app_one = MyApp(app_name='App#1')
app_one.show()
# Second instance of the MyApp
app_two = MyApp(app_name='App#2')
app_two.show()
app.exec_()