Question

在PyQt中，我想使用QAbstractItemModel和QDataWidgetMapper将小部件映射到模型数据。对于QLineEdit，它工作正常，但我想在QButtonGroup（填充了几个QRadioButton）和模型之间建立映射。因此，我将QGroupBox子类化，并添加了一个自定义属性selectedOption：

class ButtonGroupWidget(QGroupBox):
    def __init__(self, parent=None):
        super(ButtonGroupWidget, self).__init__(parent)
        self._selectedOption = -1
        self.buttonGroup = QButtonGroup()
        self.layoutGroupBox = QVBoxLayout(self)

    def addRadioButton(self,optionText,optionId):
        print(optionText)
        radioButton = QRadioButton(optionText)
        radioButton.clicked.connect(self.updateOptionSelected)
        self.layoutGroupBox.addWidget(radioButton)
        self.buttonGroup.addButton(radioButton,optionId)

    def updateOptionSelected(self):
        print(self.buttonGroup.checkedId()) # for test purpose
        self.selectedOption = self.buttonGroup.checkedId()
        print(self._selectedOption) # for test purpose

    def getSelectedOption(self):
        print("get selectedOption is called")
        return self._selectedOption

    def setSelectedOption(self,selectedOption):
        print("set selectedOption is called")
        self._selectedOption = selectedOption
        self.buttonGroup.button(selectedOption).setChecked(True)

    selectedOption = pyqtProperty(int,getSelectedOption,setSelectedOption)

在主窗口小部件中，我创建了一个ButtonGroupWidget的实例：

class MainWidget(QWidget):

    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        ...

        # insert a button group widget
        self.buttonGroupWidget1 = ButtonGroupWidget(self)
        self.buttonGroupWidget1.setTitle("Select option")
        self.buttonGroupWidget1.addRadioButton("Option 1", 1)
        self.buttonGroupWidget1.addRadioButton("Option 2", 2)
        self.buttonGroupWidget1.addRadioButton("Option 3", 3)
        ...

        # Create the data model and map the model to the widgets.
        self._model = DataModel()
        ...

        self._dataMapper = QDataWidgetMapper()
        self._dataMapper.setModel(self._model)
        ...
        # mapping to custom property
        self._dataMapper.addMapping(self.buttonGroupWidget1,1,"selectedOption")

下面给出完整代码（工作最小示例）。我的问题如下：如果模型已更改（例如，您在完整代码中看到的lineEdit），则调用setSelectedOption方法并将self._selectedOption设置为当前值并更新radioButtons。但如果我点击另一个radioButton，我不知道如何更新模型。

是否有类似于QWidget的数据更改事件，会更新模型？

有没有更好的方法将QAbstractItemModel映射到具有多个radioButtons的GroupBox？

完整代码（最小的例子，使用Python 3.4和PyQt 5.4进行测试）：

import sys
from PyQt5.QtWidgets import QWidget, QLineEdit, QRadioButton, QButtonGroup, QApplication, QVBoxLayout, QGroupBox, QTreeView,QDataWidgetMapper
from PyQt5.QtCore import QAbstractItemModel,QModelIndex,Qt,pyqtProperty

"""Base class to provide some nodes fro a tree
At the moment each node contains two members: name and option"""
class Node(object):

    def __init__(self,name,parent=None):

        self._name = name
        self._children = []
        self._parent = parent
        self._option = 2

        if parent is not None:
            parent.addChild(self)

    def name(self):
        return self._name

    def setName(self, name):
        self._name = name

    def option(self):
        return self._option

    def setOption(self,option):
        self._option = option  

    def addChild(self,child):
        self._children.append(child)

    def insertChild(self, position, child):
        if position < 0 or position > len(self._children):
            return False
        self._children.insert(position, child)
        child._parent = self
        return True

    def removeChild(self, position):
        if position < 0 or position > len(self._children):
            return False
        child = self._children.pop(position)
        child._parent = None
        return True

    def child(self,row):
        return self._children[row]

    def childCount(self):
        return len(self._children)

    def parent(self):
        return self._parent

    def row(self):
        if self._parent is not None:
            return self._parent._children.index(self)

    def __repr__(self):
        return  self.log()


class ButtonGroupWidget(QGroupBox):
    def __init__(self, parent=None):
        super(ButtonGroupWidget, self).__init__(parent)
        self._selectedOption = -1
        self.buttonGroup = QButtonGroup()
        self.layoutGroupBox = QVBoxLayout(self)

    def addRadioButton(self,optionText,optionId):
        print(optionText)
        radioButton = QRadioButton(optionText)
        radioButton.clicked.connect(self.updateOptionSelected)
        self.layoutGroupBox.addWidget(radioButton)
        self.buttonGroup.addButton(radioButton,optionId)

    def updateOptionSelected(self):
        print(self.buttonGroup.checkedId()) # for test purpose
        self.selectedOption = self.buttonGroup.checkedId()
        print(self._selectedOption) # for test purpose

    def getSelectedOption(self):
        print("get selectedOption is called")
        return self._selectedOption

    def setSelectedOption(self,selectedOption):
        print("set selectedOption is called")
        self._selectedOption = selectedOption
        self.buttonGroup.button(selectedOption).setChecked(True)

    selectedOption = pyqtProperty(int,getSelectedOption,setSelectedOption)


class DataModel(QAbstractItemModel):

    def __init__(self, parent=None):
        super(DataModel, self).__init__(parent)
        self._rootNode = Node("Root Node")
        childNode1 = Node("Child 1",self._rootNode)
        childNode2 = Node("Child 2",self._rootNode)
        childNode3 = Node("Child 3",self._rootNode)

    def __eq__(self, other): 
        return self.__dict__ == other.__dict__

    def isNull(self):
        nullObject = DataModel()
        if self.__eq__(nullObject):
            return True
        else:
            return False

    def rowCount(self, parent):
        if not parent.isValid():
            parentNode = self._rootNode
        else:
            parentNode = parent.internalPointer()
        return parentNode.childCount()

    def columnCount(self, parent):
        return 1

    def data(self,index,role):
        if not index.isValid():
            return None
        node = index.internalPointer()
        if role == Qt.DisplayRole or role == Qt.EditRole:
            if index.column() == 0:
                return node.name()
            if index.column() == 1:
                return node.option()

    def setData(self,index,value, role=Qt.EditRole):
        if index.isValid():
            node = index.internalPointer()
            if role == Qt.EditRole:
                if index.column() == 0:
                    node.setName(value)
                if index.column() == 1:
                    node.setOption(value)
                self.dataChanged.emit(index,index)
                return True            
        return False   

    def headerData(self, section, orientation, role):
        if role == Qt.DisplayRole:
            if section == 0:
                return "Select Child"

    def flags(self, index):
        return Qt.ItemIsEnabled | Qt.ItemIsSelectable | Qt.ItemIsEditable

    def parent(self, index):
        node = index.internalPointer()
        parentNode = node.parent()
        if parentNode == self._rootNode:
            return QModelIndex()
        return self.createIndex(parentNode.row(), 0, parentNode)

    def index(self, row, column, parent):

        if not parent.isValid():
            parentNode = self._rootNode
        else:
            parentNode = parent.internalPointer()

        childItem = parentNode.child(row)

        if childItem:
            return self.createIndex(row, column, childItem)
        else:
            return QModelIndex()

    def getNode(self, index):
        if index.isValid():
            node = index.internalPointer()
            if node:
                return node

        return self._rootNode

class MainWidget(QWidget):

    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        # define tree view
        self.treeView = QTreeView(self)

        # insert line edit
        self.lineEdit1 = QLineEdit(self)
        self.lineEdit2 = QLineEdit(self)

        # insert a button group widget
        self.buttonGroupWidget1 = ButtonGroupWidget(self)
        self.buttonGroupWidget1.setTitle("Select option")
        self.buttonGroupWidget1.addRadioButton("Option 1", 1)
        self.buttonGroupWidget1.addRadioButton("Option 2", 2)
        self.buttonGroupWidget1.addRadioButton("Option 3", 3)

        layoutMain = QVBoxLayout(self)
        layoutMain.addWidget(self.treeView)
        layoutMain.addWidget(self.lineEdit1)
        layoutMain.addWidget(self.lineEdit2)
        layoutMain.addWidget(self.buttonGroupWidget1)

        # Create the data model and map the model to the widgets.
        self._model = DataModel()
        self.treeView.setModel(self._model)

        self._dataMapper = QDataWidgetMapper()
        self._dataMapper.setModel(self._model)
        # the mapping works fine for line edits and combo boxes
        self._dataMapper.addMapping(self.lineEdit1, 0)
        self._dataMapper.addMapping(self.lineEdit2, 1)
        # mapping to custom property
        self._dataMapper.addMapping(self.buttonGroupWidget1,1,"selectedOption")

        self.treeView.selectionModel().currentChanged.connect(self.setSelection)

    def setSelection(self, current):

        parent = current.parent()
        self._dataMapper.setRootIndex(parent)
        self._dataMapper.setCurrentModelIndex(current) 


def main():
    app = QApplication(sys.argv)
    form = MainWidget()
    form.show()
    app.exec_()

main()

Answer 1

当单选按钮选项更改时，模型将更新，但仅在按下return或enter时才会更新。

原因是数据映射器使用item-delegate来通知对模型的更改，而item-delegate会在映射的每个窗口小部件上安装事件过滤器。但事件过滤器仅监视按键和焦点更改，而不是鼠标单击，并且无论如何，它都无法从子窗口小部件接收事件。

解决此限制的一种稍微狡猾的方法是在点击单选按钮时模拟适当的按键操作：

    def updateOptionSelected(self):
        self.selectedOption = self.buttonGroup.checkedId()
        QApplication.postEvent(
            self, QKeyEvent(QEvent.KeyPress, Qt.Key_Enter, Qt.NoModifier))

PyQt：自定义属性的QDataWidgetMapper映射

1 个答案: