ContextMenu和Hierachicaldatatemplate绑定 [英] ContextMenu and Hierachicaldatatemplate Binding

问题描述

在主窗口中，我有一个ObservableCollection的"parent"(父).项目.每个父母都有一个ObservableCollection的"device".项目.

In the MainWindow I have an ObservableCollection of "parent" items. Every parent, has an ObservableCollection of "device" items.

我的ContextMenu的第一级已正确绑定到第一个Collection的项目.问题是，对于每个MenuItem，我总是得到相同的结果(意味着每个MenuItem的数据上下文始终是相同的父"?)

The first level of my ContextMenu is properly bind to the items of the first Collection. The problem is, for every MenuItem I am getting always the same results (meaning that the datacontext for each MenuItem is always the same "parent"?)

为了更好地理解，上下文菜单看起来像这样(对不起，我无法附加任何图片或链接)

To better understand, the contextmenu looks like this (sorry, I can't attach any picture or link)

MenuItem1 -> SubItemA
MenuItem2    SubItemB
             SubItemC
________________________

MenuItem1
MenuItem2 -> SubItemA
             SubItemB
             SubItemC

我打开的每个MenuItem都会得到相同的SubItems.

Every MenuItem I open, I always get the same SubItems.

这是XAML代码:

    <StackPanel.Resources>

        <CollectionViewSource Source="{Binding Parents}" x:Key="Parents"/>

        <HierarchicalDataTemplate DataType="{x:Type local:parent}">
            <HierarchicalDataTemplate.ItemsSource>
                <Binding>
                    <Binding.Source>
                        <CompositeCollection>
                            <MenuItem Header="ParentStartAll"/>
                            <MenuItem Header="ParentStopAll"/>
                            <MenuItem Header="ParentRestartAll"/>
                            <Separator/>
                            <CollectionContainer Collection="{Binding Childs, Source={StaticResource Parents}}"/>
                        </CompositeCollection>
                    </Binding.Source>
                </Binding>
            </HierarchicalDataTemplate.ItemsSource>
            <TextBlock Text="{Binding Path=Name}"/>
        </HierarchicalDataTemplate>

        <HierarchicalDataTemplate DataType="{x:Type local:device}">
            <HierarchicalDataTemplate.ItemsSource>
                <Binding>
                    <Binding.Source>
                        <CompositeCollection>
                            <MenuItem Header="StartAll"/>
                            <MenuItem Header="StopAll"/>
                            <MenuItem Header="RestartAll"/>
                            <Separator/>
                            <CollectionContainer Collection="{Binding Processes, Source={StaticResource Parents}}"/>
                        </CompositeCollection>
                    </Binding.Source>
                </Binding>
            </HierarchicalDataTemplate.ItemsSource>
            <TextBlock Text="{Binding Path=Name}"/>
        </HierarchicalDataTemplate>


        [...]


    </StackPanel.Resources>


    <StackPanel.ContextMenu>
        <ContextMenu DataContext="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}" ItemsSource="{Binding Parents}">
        </ContextMenu>
    </StackPanel.ContextMenu>

我究竟做错了什么?另外，当我尝试第二次打开ContextMenu时，它仅显示第一级(仅父母").

What am I doing wrong? Also, when I try to open the ContextMenu for the second time, it only shows the first level (only the "parents").

有提示吗?

这里的新手很好，所以如果问题太简单或我犯了一些丑陋的错误，请不要生气.我不得不说，首先要管理绑定并不容易，而且我正在努力使此上下文菜单起作用.

Pretty newbie here, so please don't angry if the question is too easy or if I made some ugly mistakes. I have to say it was not easy to manage the binding in the firstplace and I am struggling to get this contextmenu working.

非常感谢.

推荐答案

>>问题是，对于每个MenuItem，我总是得到相同的结果(这意味着数据上下文每个MenuItem始终是相同的父项"?)

那是因为您要绑定到完全相同的父母"模板中的CollectionViewSource.此资源已定义 一次在StackPanel中，并且将始终返回相同的集合:

That's because you are binding to the exact same "Parents" CollectionViewSource in your templates. This resource is defined once in the StackPanel and will always return the same collection:

<CollectionViewSource Source="{Binding Parents}" x:Key="Parents"/>

如果要创建分层的ContextMenu，则父"菜单将显示为父".该类应该具有一个collection属性，该属性保存所有该特定父级的所有设备，并将HierarchicalDataTemplate的ItemsSource属性绑定到该属性:

If you want to create an hierarchial ContextMenu the "parent" class should have a collection property that holds all of this particular parent's devices and bind the ItemsSource property of the HierarchicalDataTemplate to this property:

<HierarchicalDataTemplate DataType="{x:Type local:parent}" ItemsSource="{Binding Devices}">
...
 

如果要在HierarchicalDataTemplate中使用CompositeCollection，则应该可以使用转换器来执行此操作.请参考以下线程以获取更多信息和示例: http://stackoverflow.com/questions/5789149/wpf-complex-hierarchical-data-template

If you want to use a CompositeCollection in your HierarchicalDataTemplate you should be able to do this using a converter. Please refer to the following thread for more information and an example: http://stackoverflow.com/questions/5789149/wpf-complex-hierarchical-data-template

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