带有 QSqlRelationalDelegate 的 QSqlRelationalTableModel 在 QAbstractProxyModel 后面不起作用

Question

我需要交换 QSqlRelationalTableModel 的行和列。经过大量搜索，我写了一个小代理模型来翻转行和列。

它正在部分工作。表中的关系已解决并显示，但选择它们的保管箱会丢失。另外，如何让他们更新？

这是一个重现该行为的独立脚本。

我的错误在哪里？我强烈怀疑它与模型的信号和槽有关，但我没有发现任何提示是哪些以及如何重新实现它们。

还有其他更简单的方法来交换行和列吗？

编辑：澄清委托模型并非完全不起作用，它只是部分起作用。

from PySide import QtCore, QtGui, QtSql
from PySide.QtCore import Qt, QModelIndex
from PySide.QtGui import QAbstractProxyModel, QWidget, QHBoxLayout, QTableView
from PySide.QtSql import QSqlRelationalDelegate


class FlipProxyModel(QAbstractProxyModel):
    def __init__(self, parent=None):
        super(FlipProxyModel, self).__init__(parent)

    def mapFromSource(self, index):
        return self.createIndex(index.column(), index.row())

    def mapToSource(self, index):
        return self.sourceModel().index(index.column(), index.row(), QModelIndex())

    def columnCount(self, parent):
        return self.sourceModel().rowCount(QModelIndex())

    def rowCount(self, parent):
        return self.sourceModel().columnCount(QModelIndex())

    def index(self, row, column, parent):
        return self.createIndex(row, column)

    def parent(self, index):
        # tables have no parent object so return empty
        return QModelIndex()

    def data(self, index, role):
        return self.sourceModel().data(self.mapToSource(index), role)

    def headerData(self, section, orientation, role):
        if orientation == Qt.Horizontal:
            return self.sourceModel().headerData(section, Qt.Vertical, role)
        if orientation == Qt.Vertical:
            return self.sourceModel().headerData(section, Qt.Horizontal, role)


def createConnection():
    db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
    db.setDatabaseName(":memory:")
    if not db.open():
        print 'fatal'
        return False
    return True

def createView(title, model):
    view = QtGui.QTableView()
    view.setModel(model)
    view.setItemDelegate(QtSql.QSqlRelationalDelegate(view))
    view.setWindowTitle(title)

    return view

if __name__ == '__main__':
    import sys
    app = QtGui.QApplication(sys.argv)
    if not createConnection():
        sys.exit(1)

    # createRelationalTables()
    query = QtSql.QSqlQuery()
    query.exec_("create table employee(id int, name varchar(20), city int, country int)")
    query.exec_("insert into employee values(1, 'Espen', 5000, 47)")
    query.exec_("insert into employee values(2, 'Harald', 80000, 49)")
    query.exec_("insert into employee values(3, 'Sam', 100, 41)")
    query.exec_("create table city(id int, name varchar(20))")
    query.exec_("insert into city values(100, 'San Jose')")
    query.exec_("insert into city values(5000, 'Oslo')")
    query.exec_("insert into city values(80000, 'Munich')")
    query.exec_("create table country(id int, name varchar(20))")
    query.exec_("insert into country values(41, 'USA')")
    query.exec_("insert into country values(47, 'Norway')")
    query.exec_("insert into country values(49, 'Germany')")

    model = QtSql.QSqlRelationalTableModel()
    model.setTable("employee")
    model.setEditStrategy(QtSql.QSqlTableModel.OnManualSubmit)
    model.setRelation(2, QtSql.QSqlRelation('city', 'id', 'name'))
    model.setRelation(3, QtSql.QSqlRelation('country', 'id', 'name'))
    model.setHeaderData(0, QtCore.Qt.Horizontal, "ID")
    model.setHeaderData(1, QtCore.Qt.Horizontal, "Name")
    model.setHeaderData(2, QtCore.Qt.Horizontal, "City")
    model.setHeaderData(3, QtCore.Qt.Horizontal, "Country")
    model.select()

    proxy = FlipProxyModel()
    proxy.setSourceModel(model)

    w = QWidget()
    layout = QHBoxLayout(w)
    view = QTableView()
    view.setModel(model)
    view.setItemDelegate(QSqlRelationalDelegate(view))
    layout.addWidget(view)

    view2 = QTableView()
    view2.setModel(proxy)
    view2.setItemDelegate(QSqlRelationalDelegate(view2))
    layout.addWidget(view2)

    w.show()
    sys.exit(app.exec_())

Answer 1

非常感谢#pyqt irc 上的一些友好陌生人。解决了。​​

答案是代理还需要一个代理模型类。

类看起来像：

class FlipProxyDelegate(QSqlRelationalDelegate):
def createEditor(self, parent, option, index):
    proxy = index.model()
    base_index = proxy.mapToSource(index)
    return super(FlipProxyDelegate, self).createEditor(parent, option, base_index)

def setEditorData(self, editor, index):
    proxy = index.model()
    base_index = proxy.mapToSource(index)
    return super(FlipProxyDelegate, self).setEditorData(editor, base_index)

def setModelData(self, editor, model, index):
    base_model = model.sourceModel()
    base_index = model.mapToSource(index)
    return super(FlipProxyDelegate, self).setModelData(editor, base_model, base_index)

它使用然后将代表替换为：

view.setItemDelegate(FlipProxyDelegate(self.tableView))