Question

我目前正在使用下面的代码在模型树中选择多行。但是在拥有大量节点的大型会话中，它可能会非常慢。我怀疑这不是很有效，因为它可能是逐个选择行。有没有什么可以加快速度 - 例如，在选择直到最后一个或在一个电话中选择全部时不刷新？

selectionModel = self.tree.selectionModel()
selectionModel.clear()

for node, i in self.tree.model().iterNodeAndIndexs():
    if nodeCondition:
        selectionModel.select(i, selectionModel.Select | selectionModel.Rows)

Answer 1

如Model/View Programming Guide中所述，您可以将左上角和右下角的索引放在QItemSelection中，然后一次选择所有单元格。

请注意，对于分层模型，您必须以递归方式在树的所有级别进行选择（请参阅selecting all notes section）。像这样：

def mySelectRows(treeView, parentIndex=None, topRow=0, bottomRow=None):

    if parentIndex is None:
        parentIndex = QtCore.QModelIndex()

    model = treeView.model()
    totalSelection = QtGui.QItemSelection()

    def populateSelection(parentIndex, topRow=0, bottomRow=None):

        if bottomRow is None:
            bottomRow = model.rowCount(parentIndex)

        leftCol, rightCol = 0, model.columnCount(parentIndex)

        topLeft = model.index(topRow, leftCol, parentIndex)
        bottomRight = model.index(bottomRow-1, rightCol-1, parentIndex)
        newSelection = QtGui.QItemSelection(topLeft, bottomRight)
        totalSelection.merge(newSelection, QtGui.QItemSelectionModel.Select)

        for row in range(topRow, bottomRow):
            childIndex = model.index(row, 0, parentIndex)
            if model.rowCount(childIndex) > 0:
                populateSelection(childIndex)

    # Start recursion
    populateSelection(parentIndex, topRow=topRow, bottomRow=bottomRow)
    selectionModel = treeView.selectionModel()
    selectionModel.select(totalSelection, 
                          QtGui.QItemSelectionModel.ClearAndSelect)

根据您对模型的实施情况，将if model.rowCount(childIndex) > 0替换为if model.hasChildren(childIndex)可能会更快

大树中最有效的PyQt模型选择

1 个答案: