python - 从 QAbstractTableModel 类中访问 View 和代理模型？

Question

使用 QTableView 和 QAbstractTableModel，我希望能够选择表格中的多个单元格并进行编辑影响所有这些选定的单元格。这就是我目前的做法，涉及将 view (QTableView) 和 proxy_model (QSortFilterProxyModel) 传递到类，以便我可以访问它们(以获取适当的行和列):

import sys
from pprint import pprint

try:
    from PySide2 import QtWidgets, QtCore
except ImportError:
    from PyQt5 import QtWidgets, QtCore


class MyTableModel(QtCore.QAbstractTableModel):
    def __init__(self,
                view,
                proxy_model,
                table_data,
                parent=None):
        QtCore.QAbstractTableModel.__init__(self, parent)

        self.table_data = table_data
        self.view = view
        self.proxy_model = proxy_model

    def rowCount(self, parent):
        return len(self.table_data)

    def columnCount(self, parent):
        return len(self.table_data[0])

    def flags(self, index):
        # Original, inherited flags:
        original_flags = super(MyTableModel, self).flags(index)

        return original_flags | QtCore.Qt.ItemIsEditable | QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable

    def data(self, index, role):
        if role == QtCore.Qt.DisplayRole:
            row = index.row()
            column = index.column()
            item = index.internalPointer()

            if item is not None:
                print(item)
            value = self.table_data[row][column]

            return value

        return None

    def setData(self, index, value, role=QtCore.Qt.EditRole):
        if role == QtCore.Qt.EditRole:
            row = index.row()
            column = index.column()

            selection_model = self.view.selectionModel()
            selected_indexes = selection_model.selectedIndexes()

            for selected_index in selected_indexes:

                mapped_index = self.proxy_model.mapToSource(selected_index)
                selected_row = mapped_index.row()
                selected_column = mapped_index.column()

                self.table_data[selected_row][selected_column] = value
                pprint(self.table_data)

                self.dataChanged.emit(index, selected_index)  # from, to

            return True

        return False


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)

    table_data = [['one', 'two', 'three'], ['four', 'five', 'six']]

    view = QtWidgets.QTableView()
    proxy_model = QtCore.QSortFilterProxyModel()
    model = MyTableModel(view=view, proxy_model=proxy_model, table_data=table_data)

    proxy_model.setSourceModel(model)
    proxy_model.setDynamicSortFilter(True)

    view.setModel(proxy_model)
    view.setSortingEnabled(True)  # requires proxy model
    view.sortByColumn(0, QtCore.Qt.AscendingOrder)
    view.horizontalHeader().setStretchLastSection(True)
    view.horizontalHeader().setSectionsMovable(True)

    view.show()
    app.exec_()

我怀疑我不必将 view 和 proxy_model 传递到类中，并且我可以通过其他方式访问这些对象。这可能吗？如果可能 - 如何实现？

---

我知道我的示例是特定于 Python 的，但我的问题实际上是一个与绑定(bind)无关的问题，因此我还用 qt 标记了我的问题。

Answer 1

基本模型不应该知道 View 或代理，所以你应该有类似下面的东西:

class MyTableModel(QtCore.QAbstractTableModel):
    def __init__(self, table_data, parent=None):
        QtCore.QAbstractTableModel.__init__(self, parent)
        self.table_data = table_data

    def rowCount(self, parent):
        return len(self.table_data)

    def columnCount(self, parent):
        return len(self.table_data[0])

    def flags(self, index):
        original_flags = super(MyTableModel, self).flags(index)
        return original_flags | QtCore.Qt.ItemIsEditable | QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable

    def data(self, index, role=QtCore.Qt.DisplayRole):
        if role == QtCore.Qt.DisplayRole:
            row = index.row()
            column = index.column()
            item = index.internalPointer()
            if item is not None:
                print(item)
            value = self.table_data[row][column]
            return value

    def setData(self, index, value, role=QtCore.Qt.EditRole):
        if role == QtCore.Qt.EditRole:
            row = index.row()
            column = index.column()
            self.table_data[row][column] = value
            self.dataChanged.emit(index, index)
            return True
        return QtCore.QAbstractTableModel.setData(self, index, value, role)

代理有将更改传递给原始模型的方法，因此通常不需要访问基础模型来进行更改，但需要访问相同的代理才能获得订单我实现了一个小部件并使用了 dataChanged() 方法，这可能会导致无限循环，因此我们必须阻止其他 dataChanged() 信号，我们使用 blockSignals() 。

class Widget(QtWidgets.QWidget):
    def __init__(self, *args, **kwargs):
        QtWidgets.QWidget.__init__(self, *args, **kwargs)
        self.view = QtWidgets.QTableView()
        self.setLayout(QtWidgets.QVBoxLayout())
        self.layout().addWidget(self.view)

        table_data = [['one', 'two', 'three'], ['four', 'five', 'six']]
        proxy_model = QtCore.QSortFilterProxyModel()
        model = MyTableModel(table_data=table_data)
        proxy_model.setSourceModel(model)
        proxy_model.setDynamicSortFilter(True)
        self.view.setModel(proxy_model)
        proxy_model.dataChanged.connect(self.on_data_changed)

        self.view.setSortingEnabled(True)  # requires proxy model
        self.view.sortByColumn(0, QtCore.Qt.AscendingOrder)
        self.view.horizontalHeader().setStretchLastSection(True)
        self.view.horizontalHeader().setSectionsMovable(True)

    def on_data_changed(self, _from, _to):
        model = _from.model() # proxy model
        model.blockSignals(True)
        for index in self.view.selectionModel().selectedIndexes():
            model.setData(index, _from.data())
        model.blockSignals(False)

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())

更新:

似乎 PySide2 有一个错误，因为它不返回所选元素而是一个空列表，因此它不会进入 for 循环，在我们为其创建该列表之前，我们使用 selectionChanged 的 selectionModel() 信号，这不会发生在 PyQt5.:

class Widget(QtWidgets.QWidget):
    def __init__(self, *args, **kwargs):
        [...]
        self.view.horizontalHeader().setSectionsMovable(True)

        self.view.selectionModel().selectionChanged.connect(self.on_selectionChanged)
        self.currentSelected = []

    def on_selectionChanged(self, selected, deselected):
        for ix in selected.indexes():
           if ix not in self.currentSelected:
            self.currentSelected.append(ix)
        for ix in deselected.indexes():
            if ix in self.currentSelected:
                self.currentSelected.remove(ix)

    def on_data_changed(self, _from, _to):
        model = _from.model() # proxy model
        model.blockSignals(True)
        pindexes = [QtCore.QPersistentModelIndex(ix) for ix in self.currentSelected]
        for index in pindexes:
            model.setData(index, _from.data())
        model.blockSignals(False)