在PyQt5中刷新窗口中的窗口小部件时是否需要重新加载整个窗口?

问题描述

我创建了一个PyQt5窗口,其中在框架中显示sql表的数据(Qtsql.QsqlTableModel,QTableView)和一个用于插入新数据的按钮(InsertButton)。为了刷新显示的表,我使用了self.MonthTab.InsertButton.clicked.connect(self.startMonth),并通过组合框中选择的年份用QSortFilterProxyModelsetFilterFixedString过滤了值,到目前为止效果还不错。 但是当我过滤条目(仅显示例如2020个条目)并插入新条目时,通过重建窗口来更新表,并且组合框被设置回认值。因此,我不再看到过滤出的2020个条目。 我想在更新表格时保留组合框设置,因此我尝试仅更新表格框架(update()hide() / show(),致电月份类(createView()handle_db),而不是“月”窗口),但更改始终是不可见的,直到(手动)重新加载“月”窗口。据我了解,startMonth将Month类元素放在Month窗口中,并且组合框必须在Month类中才能在Month窗口中看到,这在尝试更新框架而不是更新组合框时是一个难题。没道理所以大概我对PyQt窗口和QWidgets出了点问题。 是否可以在运行时仅更新窗口小部件而无需重新加载整个窗口?是否可以在“月”窗口中显示未放在“月”类中的窗口小部件?我是PyQt和Qt的新手,我用谷歌搜索并尝试了很多,但直到现在仍未成功,所以希望您能给我一个提示,指出有什么问题或如何解决

class Month(Menu):
    def __init__(self,parent=Menu):
        super(Month,self).__init__(parent)

        self.x = datetime.datetime.Now()

        self.year = QtWidgets.QComboBox(self)
        self.year.setGeometry(100,80,100,24)
        self.year.setMouseTracking(False)
        self.year.addItem(self.x.strftime("%G"))
        self.year.addItem("2019")
        self.year.addItem("2020")
        self.year.setEditable(False)

        self.year.currentTextChanged.connect(self.date_filter)

        self.InsertButton = QtWidgets.QPushButton(self)
        self.InsertButton.setText("Insert")
        self.InsertButton.clicked.connect(self.clicked)  # inserts values into sql database table

        self.handle_db()
        self.createView("Table Model (View 1)",self.model)

    def createDB(self): ... # provides sql-connection,creates database
    def initializeModel(self,model): ...
    def createView(self,title,model): ...
    def handle_db(self): ... # creates model,proxymodel,view,layout and frame for showing table
    def date_filter(self): 


class MainWindow(QMainWindow):
    def __init__(self,parent=None):
        super(MainWindow,self).__init__(parent)
        self.setGeometry(200,50,900,650)
        print("MainWindow")
        self.startMonth()


    def startMonth(self):
        self.MonthTab = Month(self)
        self.setwindowTitle("Month")
        self.setCentralWidget(self.MonthTab)
        self.MonthTab.InsertButton.clicked.connect(self.startMonth)  # rebuilds Month window -> table is updated
        self.show()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    Month().createDB()
    w = MainWindow()
    sys.exit(app.exec_())


我正在使用Python 3.8,PyQt5 5.15.0,PyCharm 2020.2和Linux Mint 19.3。

我担心“最小可复制示例”相当大:

import sys
from PyQt5 import QtWidgets,Qtsql,QtCore
from PyQt5.QtWidgets import QApplication,QMainWindow,QWidget,\
    QVBoxLayout,QTableView,QPushButton,\
    QMessageBox,qApp,qframe
from PyQt5.QtCore import QSortFilterProxyModel
import datetime


class Menu(QWidget): # die allgemeine Fenster-Parent-Class
    def __init__(self,parent=None):
        super(Menu,self).__init__()
        self.MonatBTN = QPushButton("Monat",self)
        self.MonatBTN.move(20,30)


class Monat(Menu):
    def __init__(self,parent=Menu):
        super(Monat,self).__init__(parent)

        self.x = datetime.datetime.Now()

        self.jahr = QtWidgets.QComboBox(self)

        self.jahr.setGeometry(100,24)
        self.jahr.setMouseTracking(False)
        self.jahr.addItem(self.x.strftime("%G"))
        self.jahr.addItem("2019")
        self.jahr.addItem("2020")
        self.jahr.setEditable(False)

        self.jahr.currentTextChanged.connect(self.date_filter)

        self.date_frame = qframe(self)
        self.date_frame.setFrameShape(qframe.StyledPanel)
        self.date_frame.setlinewidth(1)
        self.date_frame.setGeometry(100,500,161,50)
        self.date_picker = QtWidgets.QDateEdit(calendarPopup=True)
        self.date_picker.setDateTime(QtCore.QDateTime.currentDateTime())
        self.date_layout = QVBoxLayout()
        self.date_layout.addWidget(self.date_picker)
        self.date_frame.setLayout(self.date_layout)
        self.date_frame.show()

        self.posten = QtWidgets.QComboBox(self)
        self.posten.setGeometry(300,513,24)
        self.posten.setMouseTracking(False)
        self.posten.addItem("")
        self.posten.addItem("Apple")
        self.posten.addItem("Peach")
        self.posten.addItem("Orange")
        self.posten.setEditable(True)

        self.wert = QtWidgets.QComboBox(self)
        self.wert.setGeometry(500,24)
        self.wert.setMouseTracking(False)
        self.wert.addItem("")
        self.wert.addItem("20")
        self.wert.addItem("300")
        self.wert.addItem("-15")
        self.wert.setEditable(True)

        self.InsertButton = QtWidgets.QPushButton(self)
        self.InsertButton.setText("Einfügen")
        self.InsertButton.move(700,513)
        self.InsertButton.clicked.connect(self.clicked)

        self.handle_db()
        self.createView("Table Model (View 1)",self.model)

    def createDB(self):
        print("creating")
        self.cash_db = Qtsql.QsqlDatabase.addDatabase('QsqlITE')
        self.cash_db.setDatabaseName('cash.db')

        if not self.cash_db.open():
            QMessageBox.critical(None,qApp.tr("Cannot open database"),qApp.tr("Unable to establish a database connection.\n"
                                         "Click Cancel to exit."),QMessageBox.Cancel)
            return False

        query = Qtsql.QsqlQuery()

        # query.exec_("create table cash(id int primary key,"
        query.exec_("create table cash( "
                    "date varchar(20),datum varchar(20),posten varchar(40),wert varchar(20))")
        return True

    def initializeModel(self,model):
        self.model.setTable('cash')
        self.model.setEditStrategy(Qtsql.QsqlTableModel.OnFieldChange)
        self.model.select()
        self.model.setHeaderData(0,QtCore.Qt.Horizontal,"Date")
        self.model.setHeaderData(1,"Datum")
        self.model.setHeaderData(2,"Posten")
        self.model.setHeaderData(3,"Wert")

    def createView(self,model):
        self.view = QTableView()
        self.view.setModel(model)
        self.view.setwindowTitle(title)
        return self.view

    def handle_db(self):
        print("handling")
        self.model = Qtsql.QsqlTableModel()
        self.delrow = -1
        self.initializeModel(self.model)

        self.proxyModel = QSortFilterProxyModel()
        self.proxyModel.setSourceModel(self.model)

        self.view = self.createView("Table Model (View 1)",self.model)

        self.view.setModel(self.proxyModel)
        self.view.setSortingEnabled(True)
        self.view.hideColumn(0)

        self.view.header = self.view.horizontalHeader()
        self.view.header.resizeSection(1,100)
        self.view.header.resizeSection(2,466)
        self.view.header.resizeSection(3,100)
        self.view.resizeRowsToContents()

        self.proxyModel.setSourceModel(self.model)
        self.view.setModel(self.proxyModel)

        self.frame = qframe(self)
        self.frame.setFrameShape(qframe.StyledPanel)
        self.frame.setlinewidth(1)
        self.frame.setGeometry(100,120,700,300)

        self.layout = QVBoxLayout()
        self.layout.addWidget(self.view)

        self.frame.setLayout(self.layout)
        self.frame.show()

    def date_filter(self):
        jahr = self.jahr.currentText()
        filter = jahr
        self.proxyModel.setFilterFixedString(filter)
        self.view.resizeRowsToContents()

    def clicked(self):
        d = self.date_picker.date()
        date = d.toPyDate()
        datum = (date.strftime("%d.%m.%Y"))
        posten = self.posten.currentText()
        v = self.wert.currentText()
        val = ('%10.2f') % float(v)
        wert = str(val)

        query = Qtsql.QsqlQuery()
        query.exec_(
            "insert into cash (date,datum,posten,wert) "
            "values('%s','%s','%s')" % (date,wert))


class MainWindow(QMainWindow):
    def __init__(self,650)
        print("MainWindow")
        self.startMonat()

    def startMonat(self):
        self.MonatTab = Monat(self)
        self.setwindowTitle("Cash - Monat")
        self.setCentralWidget(self.MonatTab)
        self.MonatTab.InsertButton.clicked.connect(self.startMonat)
        self.show()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    Monat().createDB()
    w = MainWindow()
    sys.exit(app.exec_())

解决方法

如果要将数据插入表中,则必须使用与模型关联的QSqlRecord:

def clicked(self):
    d = self.date_picker.date()
    date = d.toPyDate()
    datum = date.strftime("%d.%m.%Y")
    posten = self.posten.currentText()
    v = self.wert.currentText()
    val = ("%10.2f") % float(v)
    wert = str(val)

    record = self.model.record()
    record.setValue("date",date)
    record.setValue("datum",datum)
    record.setValue("posten",posten)
    record.setValue("wert",wert)

    self.model.insertRecord(-1,record)

注意:删除self.MonatTab.InsertButton.clicked.connect(self.startMonat)

,

您可以通过专门调用widget.update()来告诉Qt随时刷新任何窗口小部件。例如,self.MonthTab.update()

但是,如果您以正确的方式使用模型和过滤器模型,则显示它们的小部件将在模型更改时自动刷新。