如何將Qlistwidget項目保存在數據庫或txt文件中

Question

您好，我最近制作了一個應用，下面將向您展示。 在pyqt5中，我想將qlistwidget項目保存在txt或數據庫文件中，但我不知道該怎么做，而且我想在運行應用程序時在qlistwidget中自動顯示保存的qlistwidget項目。 我也想從數據庫中的qlistwidget和qlistwidget中刪除選定的項目，請幫助我該怎么做，我不知道從哪里開始

我不知道該怎么做

# I am using Pyqt5
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QDialog, QInputDialog, QLineEdit


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        self.MW = MainWindow
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(288, 267)
        MainWindow.setMinimumSize(QtCore.QSize(270, 114))
        MainWindow.setMaximumSize(QtCore.QSize(630, 540))
        MainWindow.setBaseSize(QtCore.QSize(285, 260))
        MainWindow.setLayoutDirection(QtCore.Qt.LeftToRight)
        MainWindow.setStyleSheet("QMainWindow{background-color:#6F2232;}")
        MainWindow.setToolButtonStyle(QtCore.Qt.ToolButtonIconOnly)
        MainWindow.setDocumentMode(False)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setLayoutDirection(QtCore.Qt.LeftToRight)
        self.centralwidget.setStyleSheet("QWidget{background-color:#6F2232;}")
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout_2 = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout_2.setContentsMargins(9, 9, -1, -1)
        self.gridLayout_2.setObjectName("gridLayout_2")
        self.gridLayout = QtWidgets.QGridLayout()
        self.gridLayout.setContentsMargins(0, -1, -1, -1)
        self.gridLayout.setObjectName("gridLayout")
        self.listWidget = QtWidgets.QListWidget(self.centralwidget)
        font = QtGui.QFont()
        font.setPointSize(13)
        self.listWidget.setFont(font)
        self.listWidget.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.listWidget.setAutoFillBackground(False)
        self.listWidget.setStyleSheet("QListWidget{Background-color:#282828;\n"
                                      "color:#FFFFFF}")
        self.listWidget.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.listWidget.setFrameShadow(QtWidgets.QFrame.Sunken)
        self.listWidget.setLineWidth(1)
        self.listWidget.setModelColumn(0)
        self.listWidget.setObjectName("listWidget")
        self.gridLayout.addWidget(self.listWidget, 0, 0, 1, 1)
        self.gridLayout_2.addLayout(self.gridLayout, 0, 0, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 288, 21))
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.menubar.sizePolicy().hasHeightForWidth())
        self.menubar.setSizePolicy(sizePolicy)
        self.menubar.setLayoutDirection(QtCore.Qt.LeftToRight)
        self.menubar.setStyleSheet("QMenuBar{background-color:#C3083F;\n"
                                   "color:#FFFFFF}")
        self.menubar.setDefaultUp(False)
        self.menubar.setNativeMenuBar(True)
        self.menubar.setObjectName("menubar")
        self.menuFile = QtWidgets.QMenu(self.menubar)
        font = QtGui.QFont()
        font.setPointSize(9)
        font.setBold(True)
        font.setWeight(75)
        self.menuFile.setFont(font)
        self.menuFile.setLayoutDirection(QtCore.Qt.LeftToRight)
        self.menuFile.setStyleSheet("background-color:#C3083F;\n"
                                    "color:#FFFFFF;")
        self.menuFile.setToolTipsVisible(True)
        self.menuFile.setObjectName("menuFile")
        MainWindow.setMenuBar(self.menubar)
        self.toolBar = QtWidgets.QToolBar(MainWindow)
        self.toolBar.setEnabled(True)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Preferred)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.toolBar.sizePolicy().hasHeightForWidth())
        self.toolBar.setSizePolicy(sizePolicy)
        self.toolBar.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.toolBar.setLayoutDirection(QtCore.Qt.LeftToRight)
        self.toolBar.setStyleSheet("QToolBar{background-color:#282828;\n"
                                   "border:#282828;\n"
                                   "padding:2px;}\n")
        self.toolBar.setMovable(True)
        self.toolBar.setAllowedAreas(QtCore.Qt.AllToolBarAreas)
        self.toolBar.setOrientation(QtCore.Qt.Vertical)
        self.toolBar.setIconSize(QtCore.QSize(25, 39))
        self.toolBar.setFloatable(True)
        self.toolBar.setObjectName("toolBar")
        MainWindow.addToolBar(QtCore.Qt.LeftToolBarArea, self.toolBar)
        self.actionAdd = QtWidgets.QAction(MainWindow)
        icon = QtGui.QIcon()
        icon.addPixmap(QtGui.QPixmap(r"C:\Users\User\Desktop\WORK\test\task\plus.png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.actionAdd.setIcon(icon)
        self.actionAdd.setShortcutContext(QtCore.Qt.WindowShortcut)
        self.actionAdd.setAutoRepeat(True)
        self.actionAdd.setVisible(True)
        self.actionAdd.setMenuRole(QtWidgets.QAction.TextHeuristicRole)
        self.actionAdd.setIconVisibleInMenu(True)
        self.actionAdd.setShortcutVisibleInContextMenu(False)
        self.actionAdd.setObjectName("actionAdd")
        self.actionRemove = QtWidgets.QAction(MainWindow)
        icon1 = QtGui.QIcon()
        icon1.addPixmap(QtGui.QPixmap(r"C:\Users\User\Desktop\WORK\test\task\minus.png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.actionRemove.setIcon(icon1)
        self.actionRemove.setAutoRepeat(True)
        self.actionRemove.setVisible(True)
        self.actionRemove.setIconVisibleInMenu(True)
        self.actionRemove.setShortcutVisibleInContextMenu(False)
        self.actionRemove.setObjectName("actionRemove")
        self.actionUp = QtWidgets.QAction(MainWindow)
        icon2 = QtGui.QIcon()
        icon2.addPixmap(QtGui.QPixmap(r"C:\Users\User\Desktop\WORK\test\task\up-arrow (1).png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.actionUp.setIcon(icon2)
        self.actionUp.setAutoRepeat(True)
        self.actionUp.setVisible(True)
        self.actionUp.setIconVisibleInMenu(True)
        self.actionUp.setShortcutVisibleInContextMenu(False)
        self.actionUp.setObjectName("actionUp")
        self.actionDown = QtWidgets.QAction(MainWindow)
        icon3 = QtGui.QIcon()
        icon3.addPixmap(QtGui.QPixmap(r"C:\Users\User\Desktop\WORK\test\task\download.png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.actionDown.setIcon(icon3)
        self.actionDown.setAutoRepeat(True)
        self.actionDown.setVisible(True)
        self.actionDown.setIconVisibleInMenu(True)
        self.actionDown.setShortcutVisibleInContextMenu(False)
        self.actionDown.setObjectName("actionDown")
        self.actionSort = QtWidgets.QAction(MainWindow)
        icon4 = QtGui.QIcon()
        icon4.addPixmap(QtGui.QPixmap(r"C:\Users\User\Desktop\WORK\test\task\sort (1).png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.actionSort.setIcon(icon4)
        self.actionSort.setAutoRepeat(True)
        self.actionSort.setVisible(True)
        self.actionSort.setIconVisibleInMenu(True)
        self.actionSort.setShortcutVisibleInContextMenu(False)
        self.actionSort.setObjectName("actionSort")
        self.actionNotepad = QtWidgets.QAction(MainWindow)
        icon5 = QtGui.QIcon()
        icon5.addPixmap(QtGui.QPixmap(":/task/spiral_bound_booklet_64px.png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.actionNotepad.setIcon(icon5)
        self.actionNotepad.setObjectName("actionNotepad")
        self.menuFile.addAction(self.actionAdd)
        self.menuFile.addAction(self.actionRemove)
        self.menuFile.addAction(self.actionUp)
        self.menuFile.addAction(self.actionDown)
        self.menuFile.addAction(self.actionSort)
        self.menuFile.addAction(self.actionNotepad)
        self.menubar.addAction(self.menuFile.menuAction())
        self.toolBar.addAction(self.actionAdd)
        self.toolBar.addAction(self.actionRemove)
        self.toolBar.addAction(self.actionUp)
        self.toolBar.addAction(self.actionDown)
        self.toolBar.addAction(self.actionSort)
        self.actionAdd.triggered.connect(self.actAdd)
        self.actionRemove.triggered.connect(self.actRemove)
        self.actionUp.triggered.connect(self.actUp)
        self.actionDown.triggered.connect(self.actDown)
        self.actionSort.triggered.connect(self.actSort)
        #self.actionRemove.triggered.connect(self.actEdit)
        self.retranslateUi(MainWindow)

        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.menuFile.setTitle(_translate("MainWindow", "File"))
        self.toolBar.setWindowTitle(_translate("MainWindow", "toolBar"))
        self.actionAdd.setText(_translate("MainWindow", "Add"))
        self.actionRemove.setText(_translate("MainWindow", "Remove"))
        self.actionUp.setText(_translate("MainWindow", "Up"))
        self.actionDown.setText(_translate("MainWindow", "Down"))
        self.actionSort.setText(_translate("MainWindow", "Sort"))
        self.actionNotepad.setText(_translate("MainWindow", "Notepad"))

    #Here when I will trigger this function I want to add item 
    #qlistwidget and also add what I wrote in database or txt file 
    #AUTOMATICALLY. I dont know how to do it please help

    def actAdd(self):
        row = self.listWidget.currentRow()
        QInputDialog.setStyleSheet(self.MW,"QInputDialog{background-color:#C3083F;}")
        text, ok = QInputDialog.getText(self.MW,"Add","Add Task")
        if ok and text is not None:
            self.listWidget.insertItem(row,text)

    # Here I want to remove qlistwidget item and remove it from database or in 
    # txt file too

    def actRemove(self):
        row = self.listWidget.currentRow()
        item = self.listWidget.item(row)
        if item is None:
            return
        else:
            item = self.listWidget.takeItem(row)
            del item

    def actUp(self):
        row = self.listWidget.currentRow()
        if row >=1:
            item = self.listWidget.takeItem(row)
            self.listWidget.insertItem(row -1, item)
            self.listWidget.setCurrentItem(item)

    def actDown(self):
        row = self.listWidget.currentRow()
        if row < self.listWidget.count() -1:
            item = self.listWidget.takeItem(row)
            self.listWidget.insertItem(row +1, item)
            self.listWidget.setCurrentItem(item)

    def actSort(self):
        self.listWidget.sortItems()


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_())

Answer 1

不必在每次添加或刪除列表中的條目時將數據寫入磁盤，而只能在應用程序存在時才將數據寫入磁盤。 可以通過子類化QMainWindow並重寫closeEvent來實現，如下面的示例所示。 在此示例中，數據保存到save_file.txt 。 要在啟動窗口時自動讀取保存的數據，可以覆蓋MyMainWindow.__init__ ，例如

# Ui_MainWindow() as before

class MyMainWindow(QtWidgets.QMainWindow):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.save_file = 'save_file.txt'
        self.read_from_file(self.save_file)

    def write_to_file(self, file):
        try:
            list_widget = self.ui.listWidget
            entries = '\n'.join(list_widget.item(ii).text() for ii in range(list_widget.count()))
            with open(file, 'w') as fout:
                fout.write(entries)
        except OSError as err:
            print(f"file {file} could not be written")

    def read_from_file(self, file):
        try:
            list_widget = self.ui.listWidget
            with open(file, 'r') as fin:
                entries = [e.strip() for e in fin.readlines()]
            list_widget.insertItems(0, entries)
        except OSError as err:
            with open(file, 'w'):
                pass

    def closeEvent(self, event):
        should_save = QtWidgets.QMessageBox.question(self, "Save data", 
                                                     "Should the data be saved?",
                                                     defaultButton = QtWidgets.QMessageBox.Yes)
        if should_save == QtWidgets.QMessageBox.Yes:
            self.write_to_file(self.save_file)
        return super().closeEvent(event)


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = MyMainWindow()
    MainWindow.show()
    sys.exit(app.exec_())