qtreeview:拖放子树会导致选择错误

时间:2013-03-14 15:24:34

标签: c++ qt drag-and-drop qtreeview

我一直试图在qtreeview中拖放一个子树。当我执行drop并更新底层模型时,树正确地重新排序,然而,项目选择随后被搞砸了。我无法想出一种可靠的方法来强制QT适当地重新绘制选择。请参见下面的屏幕截图:

在:

Before Drag and Drop

将顶部节点拖动到节点2后:

enter image description here

相关观点代码:

void View::dropEvent(QDropEvent *evt)
{
    QTreeView::dropEvent(evt);

    QModelIndex start = indexAt(_drag_start);
    QModelIndex end = indexAt(evt->pos());

    _model->moveTo(start, end);
}

相关型号代码:

void Model::moveTo(QModelIndex& start, QModelIndex& end)
{
    // ... omitted some error checking code to ensure start and end have the same parent

    ModelData* a = (ModelData*) start.internalPointer();
    ModelData* b = (ModelData*) end.internalPointer();

    ModelData* list = (ModelData*) (parent(start).internalPointer());

    int idxa = list->indexOf(a);
    int idxb = list->indexOf(b);

    // underneath this is QList<...>::moveTo
    list->moveTo( idxa, idxb );

    QModelIndex p = this->parent(start);

    emit dataChanged( index(0, 0, p), index(rowCount(p)-1, 1, p) );
}

有什么建议吗?谢谢!

1 个答案:

答案 0 :(得分:0)

结果证明这是通过在Model :: moveTo()方法中添加以下代码来解决的:

...
emit layoutAboutToBeChanged();
list->moveTo( ... );
emit layoutChanged();
...