如何在Qt或PyQt中使用QDataWidgetMapper？

Question

我可以找到一些关于如何在标准视图中使用标准模型的示例。

http://doc.qt.io/qt-5/modelview.html

http://doc.qt.io/qt-5/qtwidgets-itemviews-simplewidgetmapper-example.html

但我找不到一个如何使用 QAbstractModel 制作我自己的 model 并自己使用它的示例 view/widget。

更新模型后，展台视图会更新，但我自己的视图不会更新。

完整代码：

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from  PyQt5.QtWidgets import (QWidget, QLabel, QDataWidgetMapper,
                              QLineEdit, QApplication, QGridLayout)
from PyQt5.QtCore import QAbstractListModel, Qt
from PyQt5.QtWidgets import QListView


class Window(QWidget):
    def __init__(self, model, parent=None):
        super(Window, self).__init__(parent)

        self.model = model

        # Set up the widgets.
        nameLabel = QLabel("Na&me:")
        nameEdit = QLineEdit()

        # Set up the mapper.
        self.mapper = QDataWidgetMapper(self)
        self.mapper.setModel(self.model)
        self.mapper.addMapping(nameEdit, 0)

        layout = QGridLayout()
        layout.addWidget(nameLabel, 0, 0, 1, 1)
        layout.addWidget(nameEdit, 0, 1, 1, 1)
        self.setLayout(layout)

        self.mapper.toFirst()


class MyModel(QAbstractListModel):
    def __init__(self, status=[], parent=None):
        super().__init__(parent)
        self.status = status

    def rowCount(self, index_parent=None, *args, **kwargs):
        return len(self.status)

    def data(self, index, role=Qt.DisplayRole, parent=None):
        if not index.isValid():
            return None
        row = index.row()
        if row == 0:
            print(index)
            if role == Qt.DisplayRole:
                return self.status[row]
            elif role == Qt.EditRole:  # if it's editing mode, return value for editing

                return self.status[row]

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

    def setData(self, index, value='', role=Qt.EditRole):
        row = index.row()

        if role == Qt.EditRole:
            self.status[row] = value
            self.dataChanged.emit(index, index)  # inform the other view to request new data
            return True
        else:
            return False


if __name__ == '__main__':
    import sys

    app = QApplication(sys.argv)

    myModel_on_mywindow = MyModel([1, 2, 3])
    mywindow = Window(myModel_on_mywindow)
    mywindow.setWindowTitle('myModel_on_mywindow')
    mywindow.show()
    myModel_on_mywindow.status[0] = 2

    myModel_on_qlistview = MyModel([1, 2, 3])
    qlistview = QListView()
    qlistview.show()
    qlistview.setModel(myModel_on_qlistview)
    qlistview.setWindowTitle('myModel_on_qlistview')

    myModel_on_qlistview.status[0] = 2

    sys.exit(app.exec_())

Answer 1

您的自定义模型需要覆盖抽象模型的某些功能，具体取决于您将哪个子类化。这是一个子类化 QAbstractListModel 的小例子。您可以在 Qt 文档中阅读更多相关信息：QAbstractListModel Details

class MyModel(QAbstractListModel):
    def __init__(parent=None):
        QAbstractListModel.__init__(parent)
        self.content = []  # holds the data, you want to present

    def rowCount(index):
        return len(self.content)
    # This defines what the view should present at given index
    def data(index, role):
        if index.isValid() and role == Qt.DisplayRole):
            dataElement = self.content[index.row()]
            if index.colum() == 0:
                return dataElement.someBoolField
            if index.colum() == 1:
                return dataElement.someIntField
            # ...
        }
        return QVariant()  # this is like returning nothing
    }
    # If your items should be editable. Automatically called, when user changes the item.
    def setData(index, value, role):
        if index.isValid():
            dataElement = self.content[index.row()].get()
            if index.column() == 0:
                return dataElement.tryToSetBoolField(value.toBool())
            if index.column() == 1:
                return dataElement.tryToSetIntField(value.toInt())
            # ...
        }
        return True
    }
};

# connecting your view with your model
model = MyModel()
myView = QTreeView()  # or something else
myView.setModel(model)

编辑

要在结合使用自定义模型和 QDataMapper 时更新您的视图，请在更改模型后调用 setCurrentIndex(changedIndex) 或其包装器，就像您的情况一样：

myModel_on_mywindow.status[0] = 2
myModel.mapper.toFirst()

QDataMapper 上的 Qt 文档在详细说明中提到了这一点：

The navigational functions toFirst(), toNext(), toPrevious(), toLast() and setCurrentIndex() can be used to navigate in the model and update the widgets with contents from the model.

如何在Qt或PyQt中使用QDataWidgetMapper？

How to use QDataWidgetMapper in Qt or PyQt?

python

model-view-controller

user-interface

qt

pyqt