python - 如何将选定的项目从 QListWidget、QTableWidget 保存到 Qsettings

Question

我正在使用 PyQt5 和 Py3.7，我试图循环遍历所有 Qlistwidgets 并保存它们的字符串数据，同时也保存该小部件上的所有选定项目。我稍微修改了 here 中的循环，但是使用 listwidget 数组循环保存和恢复所选项目时遇到一些问题。我检查了文档，但似乎无法理解如何向数组中添加其他选项(例如保存所有选定的项目)，来自 SetArrayIndex 的 Qt 文档，here .

我的 listWidgets 将 SelectionMode 设置为 MultiSelection。我目前正在使用这个进行保存:

def save_list_data(self):
    self.settings = QSettings("data.ini", QSettings.IniFormat)
    for name, obj in inspect.getmembers(self):
        if isinstance(obj, QListWidget):
            name = obj.objectName()
            self.settings.beginWriteArray(name)
            for i in range(obj.count()):
                self.settings.setArrayIndex(i)
                self.settings.setValue(name, obj.item(i).text())
            self.settings.endArray()

然后使用以下方法恢复 listWidget 数据:

def open_list_data(self):
    self.settings = QSettings("data.ini", QSettings.IniFormat)
    for name, obj in inspect.getmembers(self):
        if isinstance(obj, QListWidget):
            name = obj.objectName()
            size = self.settings.beginReadArray(name)
            for i in range(size):
                self.settings.setArrayIndex(i)
                value = self.settings.value(name)
                if value != None:
                    obj.addItem(value)
            self.settings.endArray()

这对于数据来说效果很好，但是我如何从 ListWidgets 中获取 selectedItems 来保存和恢复？

Answer 1

对于我的解决方案，请考虑以下因素:

• 使用检查模块可能对其他库有益，但对于 Qt 来说，小部件不一定是类的成员，因此最好使用 findChildren 来使用 Qt 内省(introspection)本身。

• 在您使用的示例中，您仅保存文本，但 QListWidgetItem 可以包含与角色相关的更多信息，例如背景颜色、前景色等。因此，我将使用 QDataStream 运算符，因为这需要并保存获取项目信息。

• 我将使用“对象名称/属性”格式来保存信息，因为同一个小部件可以具有您要保存的多个属性。

• 要保存所选项目的信息，只需保存该行即可。

考虑到上述情况，解决方案是:

from PyQt5 import QtCore, QtGui, QtWidgets


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.listwidget_1 = QtWidgets.QListWidget(
            objectName="listwidget_1", 
            selectionMode=QtWidgets.QAbstractItemView.MultiSelection
        )
        listwidget_2 = QtWidgets.QListWidget(
            objectName="listwidget_2", 
            selectionMode=QtWidgets.QAbstractItemView.MultiSelection
        )

        lay = QtWidgets.QVBoxLayout(self)
        lay.addWidget(self.listwidget_1)
        lay.addWidget(listwidget_2)

        self.read_settings()

    def closeEvent(self, event):
        self.write_settings()
        super().closeEvent(event)

    def read_settings(self):
        settings = QtCore.QSettings("data.ini", QtCore.QSettings.IniFormat)
        childrens = self.findChildren(QtWidgets.QWidget)
        for children in childrens:
            if isinstance(children, QtWidgets.QListWidget) and children.objectName():
                settings.beginGroup(children.objectName())
                items = settings.value("items")
                selecteditems = settings.value("selecteditems")
                selectionMode = settings.value("selectionMode", type=QtWidgets.QAbstractItemView.SelectionMode)
                children.setSelectionMode(selectionMode)
                # In the first reading the initial values must be established
                if items is None:
                    if children.objectName() == "listwidget_1":
                        for i in range(10):
                            children.addItem(QtWidgets.QListWidgetItem(str(i)))
                    elif children.objectName() == "listwidget_2":
                        for i in "abcdefghijklmnopqrstuvwxyz":
                            children.addItem(QtWidgets.QListWidgetItem(i))
                else:
                    stream = QtCore.QDataStream(items, QtCore.QIODevice.ReadOnly)
                    while not stream.atEnd():
                        it = QtWidgets.QListWidgetItem()
                        stream >> it
                        children.addItem(it)
                    stream = QtCore.QDataStream(selecteditems, QtCore.QIODevice.ReadOnly)
                    while not stream.atEnd():
                        row = stream.readInt()
                        it = children.item(row)
                        it.setSelected(True)
                settings.endGroup()

    def write_settings(self):
        settings = QtCore.QSettings("data.ini", QtCore.QSettings.IniFormat)
        childrens = self.findChildren(QtWidgets.QWidget)
        for children in childrens:
            if isinstance(children, QtWidgets.QListWidget) and children.objectName():
                settings.beginGroup(children.objectName())
                items = QtCore.QByteArray()
                stream = QtCore.QDataStream(items, QtCore.QIODevice.WriteOnly)
                for i in range(children.count()):
                    stream << children.item(i)
                selecteditems = QtCore.QByteArray()
                stream = QtCore.QDataStream(selecteditems, QtCore.QIODevice.WriteOnly)
                for it in children.selectedItems():
                    stream.writeInt(children.row(it))
                settings.setValue("items", items)
                settings.setValue("selecteditems", selecteditems)
                settings.setValue("selectionMode", children.selectionMode())
                settings.endGroup()


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

加号:

import contextlib
from PyQt5 import QtCore, QtGui, QtWidgets


class SettingsManager:
    def __init__(self, filename):
        self.m_settings = QtCore.QSettings(filename, QtCore.QSettings.IniFormat)

    @property
    def settings(self):
        return self.m_settings

    def read(self, widget):
        self.settings.beginGroup(widget.objectName())
        if isinstance(widget, QtWidgets.QAbstractItemView):
            selectionMode = self.settings.value(
                "selectionMode", type=QtWidgets.QAbstractItemView.SelectionMode
            )
            widget.setSelectionMode(selectionMode)
        if isinstance(widget, QtWidgets.QListWidget):
            items = self.settings.value("items")
            selecteditems = self.settings.value("selecteditems")
            # In the first reading the initial values must be established
            if items is None:
                self.read_defaults(widget)
            else:
                stream = QtCore.QDataStream(items, QtCore.QIODevice.ReadOnly)
                while not stream.atEnd():
                    it = QtWidgets.QListWidgetItem()
                    stream >> it
                    widget.addItem(it)
                stream = QtCore.QDataStream(
                    selecteditems, QtCore.QIODevice.ReadOnly
                )
                while not stream.atEnd():
                    row = stream.readInt()
                    it = widget.item(row)
                    if it is not None:
                        it.setSelected(True)
        if isinstance(widget, QtWidgets.QTableWidget):
            rowCount = self.settings.value("rowCount", type=int)
            columnCount = self.settings.value("columnCount", type=int)
            widget.setRowCount(rowCount)
            widget.setColumnCount(columnCount)
            items = self.settings.value("items")
            if items is None:
                self.read_defaults(widget)
            else:
                stream = QtCore.QDataStream(items, QtCore.QIODevice.ReadOnly)
                while not stream.atEnd():
                    it = QtWidgets.QTableWidgetItem()
                    i = stream.readInt()
                    j = stream.readInt()
                    stream >> it
                    widget.setItem(i, j, it)
                selecteditems = self.settings.value("selecteditems")
                stream = QtCore.QDataStream(
                    selecteditems, QtCore.QIODevice.ReadOnly
                )
                while not stream.atEnd():
                    i = stream.readInt()
                    j = stream.readInt()
                    it = widget.item(i, j)
                    if it is not None:
                        it.setSelected(True)
        self.settings.endGroup()

    def write(self, widget):
        self.settings.beginGroup(widget.objectName())
        if isinstance(widget, QtWidgets.QAbstractItemView):
            self.settings.setValue("selectionMode", widget.selectionMode())
        if isinstance(widget, QtWidgets.QListWidget):
            items = QtCore.QByteArray()
            stream = QtCore.QDataStream(items, QtCore.QIODevice.WriteOnly)
            for i in range(widget.count()):
                stream << widget.item(i)
            self.settings.setValue("items", items)
            selecteditems = QtCore.QByteArray()
            stream = QtCore.QDataStream(
                selecteditems, QtCore.QIODevice.WriteOnly
            )
            for it in widget.selectedItems():
                stream.writeInt(widget.row(it))

            self.settings.setValue("selecteditems", selecteditems)
        if isinstance(widget, QtWidgets.QTableWidget):
            self.settings.setValue("rowCount", widget.rowCount())
            self.settings.setValue("columnCount", widget.columnCount())
            items = QtCore.QByteArray()
            stream = QtCore.QDataStream(items, QtCore.QIODevice.WriteOnly)
            for i in range(widget.rowCount()):
                for j in range(widget.columnCount()):
                    it = widget.item(i, j)
                    if it is not None:
                        stream.writeInt(i)
                        stream.writeInt(j)
                        stream << it
            self.settings.setValue("items", items)
            selecteditems = QtCore.QByteArray()
            stream = QtCore.QDataStream(
                selecteditems, QtCore.QIODevice.WriteOnly
            )
            for it in widget.selectedItems():
                # print(it.row(), it.column())
                stream.writeInt(it.row())
                stream.writeInt(it.column())
            self.settings.setValue("selecteditems", selecteditems)
        self.settings.endGroup()

    def release(self):
        self.m_settings.sync()

    def read_defaults(self, widget):
        if widget.objectName() == "listwidget_1":
            widget.setSelectionMode(QtWidgets.QAbstractItemView.MultiSelection)
            for i in range(10):
                widget.addItem(QtWidgets.QListWidgetItem(str(i)))
        elif widget.objectName() == "listwidget_2":
            widget.setSelectionMode(QtWidgets.QAbstractItemView.MultiSelection)
            for i in "abcdefghijklmnopqrstuvwxyz":
                widget.addItem(QtWidgets.QListWidgetItem(i))
        elif widget.objectName() == "tablewidget":
            widget.setSelectionMode(QtWidgets.QAbstractItemView.MultiSelection)
            widget.setRowCount(10)
            widget.setColumnCount(10)
            for i in range(widget.rowCount()):
                for j in range(widget.columnCount()):
                    it = QtWidgets.QTableWidgetItem("{}-{}".format(i, j))
                    widget.setItem(i, j, it)


@contextlib.contextmanager
def settingsContext(filename):
    manager = SettingsManager(filename)
    try:
        yield manager
    finally:
        manager.release()


class Widget(QtWidgets.QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.listwidget_1 = QtWidgets.QListWidget(objectName="listwidget_1")
        listwidget_2 = QtWidgets.QListWidget(objectName="listwidget_2")

        tablewidget = QtWidgets.QTableWidget(objectName="tablewidget")

        lay = QtWidgets.QVBoxLayout(self)
        lay.addWidget(self.listwidget_1)
        lay.addWidget(listwidget_2)
        lay.addWidget(tablewidget)

        self.read_settings()

    def closeEvent(self, event):
        self.write_settings()
        super().closeEvent(event)

    def read_settings(self):
        with settingsContext("data.ini") as m:
            for children in self.findChildren(QtWidgets.QWidget):
                if children.objectName():
                    m.read(children)

    def write_settings(self):
        with settingsContext("data.ini") as m:
            for children in self.findChildren(QtWidgets.QWidget):
                if children.objectName():
                    m.write(children)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.resize(640, 480)
    w.show()
    sys.exit(app.exec_())