Treeview如何判断用户何时通过拖动节点重新组织树视图 [英] Treeview how do I tell when the user reorganizes the treeview by dragging nodes

问题描述

我有一个用户可以编辑的TreeView。我需要知道它何时发生变化，以便我能坚持下去。我做了添加和删除，所以这没问题。但是用户也可以通过拖放节点来重构树。我无法确定在发生这种情况时应该聆听什么事件。



我尝试了什么：



我尝试过拖放事件，但是他们没有被发现。我想TreeView会自己吃掉它们。我已经考虑过继承TreeViewNode并覆盖可能在这种情况下使用的所有Children IList成员，但确定必须有更文明的方式。

I have a TreeView that the user can edit. I need to know whenever it changes so that I can persist it. I do the additions and deletions, so that is no problem. But the user can also restructure the tree by dragging and dropping the nodes. I haven't been able to determine what event(s) to listen for to tell when that is happening.

What I have tried:

I've tried the Drag and Drop events, but they were uncalled. I suppose the TreeView eats them itself. I've considered subclassing TreeViewNode and overriding all the Children IList members that could be used in that case, but was sure there must be a more civilised way.

推荐答案

TreeView本身不公开任何指示用户已更改树结构的事件，TreeView控件包装TreeViewList控件。该控件确实暴露了拖动事件，如DragItemStarting。因此解决方案是这样做：

While the TreeView itself does not expose any events that indicate that the user has changed the structure of the tree, the TreeView control wraps a TreeViewList control. That control does expose drag events, like DragItemStarting. So the solution is to do this:

<Style TargetType="TreeView">
            <Setter Property="IsTabStop" Value="False" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="TreeView">
                        <TreeViewList x:Name="ListControl"
                                      DragItemsCompleted="DragItemsCompleted"
                                      CanDragItems="True"
                                      AllowDrop="True"
                                      CanReorderItems="True">

感谢来自微软的Sunteen Wu的回答！

Thanks to Sunteen Wu from Microsoft for the answer!

也许是拖累和放大UWP TreeView不支持drop？



在uwp中的树视图之间拖放 - Stack Overflow [ ^ ]

Maybe drag & drop is not supported for a UWP TreeView?

Drag and drop between treeview in uwp - Stack Overflow[^]

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