如何从PyQt4中的QVariant取回python对象? [英] How do I get my python object back from a QVariant in PyQt4?

问题描述

我正在创建QAbstractItemModel的子类，以显示在QTreeView中.

I am creating a subclass of QAbstractItemModel to be displayed in an QTreeView.

我的index()和parent()函数使用QAbstractItemModel继承的函数createIndex并提供所需的row，column和data来创建QModelIndex.在这里，出于测试目的，数据是一个Python字符串.

My index() and parent() function creates the QModelIndex using the QAbstractItemModel inherited function createIndex and providing it the row, column, and data needed. Here, for testing purposes, data is a Python string.

class TestModel(QAbstractItemModel):
    def __init__(self):
        QAbstractItemModel.__init__(self)

    def index(self, row, column, parent):
        if parent.isValid():
            return self.createIndex(row, column, "bar")
        return self.createIndex(row, column, "foo")

    def parent(self, index):
        if index.isValid():
            if index.data().data() == "bar":                          <--- NEVER TRUE
                return self.createIndex(0, 0, "foo")
        return QModelIndex()

    def rowCount(self, index):
        if index.isValid():
            if index.data().data() == "bar":                          <--- NEVER TRUE
                return 0
        return 1

    def columnCount(self, index):
        return 1

    def data(self, index, role):
        if index.isValid():
            return index.data().data()                                <--- CANNOT DO ANYTHING WITH IT
        return "<None>"

在index()，parent()和data()函数中，我需要取回数据.它以QVariant的形式出现.如何从QVariant取回我的Python对象?

Within the index(), parent(), and data() functions I need to get my data back. It comes as a QVariant. How do I get my Python object back from the QVariant?

推荐答案

关键是直接在QModelIndex上使用internalPointer()，而根本不使用QVariant.

The key thing is to use internalPointer() directly on the QModelIndex, not dealing with the QVariant at all.

class TestModel(QAbstractItemModel):
    def __init__(self, plan):
        QAbstractItemModel.__init__(self)

    def index(self, row, column, parent):
        if not parent.isValid():
            return self.createIndex(row, column, "foo")
        return self.createIndex(row, column, "bar")

    def parent(self, index):
         if index.internalPointer() == "bar":
            return self.createIndex(0, 0, "foo")
        return QModelIndex()

    def rowCount(self, index):
        if index.internalPointer() == "bar":
            return 0
        return 1

    def columnCount(self, index):
        return 1

    def data(self, index, role):
        if role == 0:  # Qt.DisplayRole
            return index.internalPointer()
        else:
            return None

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