在 QMainWindow 中添加 QWidget，它在 PyQt 中已经有一个中心小部件

问题描述

我正在 PyQt 中开发一个 GUI 应用程序。

对于按钮，我使用了 QWidget，对于 QsqlTable，我使用了 QMainWindow。

我知道我可以通过在 QMainWindow 中添加 setCentralwidget 来添加 QWidget。 但是为了显示表格，我需要表格作为中央小部件。

两者都可以单独工作，但我无法同时拥有两者。

我的代码如下：

import sys
from PyQt5 import QtCore,QtWidgets
from PyQt5.QtWidgets import QVBoxLayout,qgroupbox,qgridLayout,QPushButton,QLabel.  
from PyQt5.QtGui import Qpixmap
from PyQt5 import QtGui
from gwWindow import groundwaterWindow
from swWindow import surfacewaterWindow
from kwWindow import karstwaterWindow
from PyQt5.QtCore import Qt,QModelIndex
from PyQt5.Qtsql import QsqlDatabase,QsqlTableModel,QsqlQuery
from PyQt5.QtWidgets import (QApplication,QMainWindow,QMessageBox,QTableView,QVBoxLayout)
from PyQt5 import QtCore
from PyQt5.QtCore import pyqtSignal


class MainWindow(QtWidgets.QWidget):
    def __init__(self):
        QtWidgets.QWidget.__init__(self)
        self.title = "PPCP Selection"
        self.top = 100

        self.left = 100
        self.width = 1200
        self.height = 1200


        self.Initwindow()

    def Initwindow(self):
        self.setwindowTitle(self.title)
        self.setGeometry(self.top,self.left,self.width,self.height)

        self.createLayout()

        vBoxLayout = QVBoxLayout()

        vBoxLayout.addWidget(self.groupBox1)
        # vBoxLayout.addWidget(self.groupBox2)
        self.setLayout(vBoxLayout)
        # self.showMaximized()

    def createLayout(self):
        self.groupBox1 = qgroupbox("PPCP Selection")
        self.groupBox1.setFont(QtGui.QFont("Arial",30))
        gridLayout = qgridLayout()
        gridLayout.setRowStretch(2,2)


        self.button1 = QPushButton("Evaluate")
        gridLayout.addWidget(self.button1,1,1)
        #self.button1.clicked.connect(self.switch1)
        gridLayout.addWidget(self.button1)
        self.button1.setFocusPolicy(QtCore.Qt.NoFocus)

        self.groupBox1.setLayout(gridLayout)


class RealMainWindow(QMainWindow):
    def __init__(self,parent=None):
        super().__init__(parent)
        self.setwindowTitle("QTableView Example")
        self.resize(415,200)
        # Set up the model
        self.model = TableModel(self)
        self.model.setTable("Table2")
        self.model.setEditStrategy(QsqlTableModel.OnFieldChange)
        #self.model.setHeaderData(0,Qt.Horizontal,"ID")


        self.model.select()
        # Set up the view
        self.view = QTableView()
        self.view.setModel(self.model)
        #self.view.resizeColumnsToContents()

        self.another = MainWindow()

        # I want both of the following


        # self.setCentralWidget(self.view)
        # self.setCentralWidget(self.another)

    def secondWindow(self):
        self.another = MainWindow()
        self.another.show()



class TableModel(QsqlTableModel):
    def __init__(self,*args,**kwargs):
        QsqlTableModel.__init__(self,**kwargs)
        self.checkeable_data = {}

    def flags(self,index):
        fl = QsqlTableModel.flags(self,index)
        if index.column() == 0:
            fl |= Qt.ItemIsUserCheckable
        return fl

    def data(self,index,role=Qt.displayRole):
        if role == Qt.CheckStateRole and (
            self.flags(index) & Qt.ItemIsUserCheckable != Qt.NoItemFlags
        ):
            if index.row() not in self.checkeable_data.keys():
                self.setData(index,Qt.Unchecked,Qt.CheckStateRole)
            return self.checkeable_data[index.row()]
        else:
            return QsqlTableModel.data(self,role)

    def setData(self,value,role=Qt.EditRole):
        if role == Qt.CheckStateRole and (
            self.flags(index) & Qt.ItemIsUserCheckable != Qt.NoItemFlags
         ):
            self.checkeable_data[index.row()] = value
            self.dataChanged.emit(index,(role,))
            return True
        return QsqlTableModel.setData(self,role)


def createConnection():

    con = QsqlDatabase.addDatabase("QsqlITE")
    con.setDatabaseName("ppcp_database.db")
    if not con.open():
        QMessageBox.critical(
            None,"QTableView Example - Error!","Database Error: %s" % con.lastError().databaseText(),)
        return False
    return True

app = QApplication(sys.argv)
if not createConnection():
  sys.exit(1)
win = RealMainWindow()
win.show()
sys.exit(app.exec_())

解决方法

使用 Qt 布局：

class RealMainWindow(QMainWindow):
    def __init__(self,parent=None):
        super().__init__(parent)
        self.setWindowTitle("QTableView Example")
        self.resize(415,200)

        # Set up the model
        self.model = TableModel(self)
        self.model.setTable("Table2")
        self.model.setEditStrategy(QSqlTableModel.OnFieldChange)
        self.model.select()

        self.view = QTableView()
        self.view.setModel(self.model)

        self.another = MainWindow()

        central_widget = QWidget()
        self.setCentralWidget(central_widget)
        lay = QVBoxLayout(central_widget)
        lay.addWidget(self.view)
        lay.addWidget(self.another)