具有相同CollectionViewSource ItemSource的两个组合框相互更新 [英] Two comboboxes with the same CollectionViewSource ItemSource update each other

问题描述

在我的ViewModel上，我有两个属性（都实现属性更改的通知）：

On my ViewModel, I have 2 properties (both implement property changed notifications) :

CountryOfIssue
Nationality

在我的视图中，我有一个CollectionViewSource指向我的实体框架上下文的本地实例：

On my View, I have a CollectionViewSource pointing to a local instance of my Entity Framework context :

<CollectionViewSource x:Key="cvsCountries" Source="{Binding LocalContext.Countries}" CollectionViewType="{x:Type ListCollectionView}">
    <CollectionViewSource.SortDescriptions>
        <scm:SortDescription PropertyName="Name" />
    </CollectionViewSource.SortDescriptions>
</CollectionViewSource>

另外在这个页面上，我有两个组合框用于设置CountryOfIssue和国籍的值： p>

Also on this page, I have two comboboxes used to set the values of CountryOfIssue and Nationality :

<ComboBox IsEnabled="{Binding CanEditCountryOfIssue}" ItemsSource="{Binding Source={StaticResource cvsCountries}}" DisplayMemberPath="Name" SelectedValuePath="Id" SelectedItem="{Binding CountryOfIssue, Mode=TwoWay, UpdateSourceTrigger=LostFocus, ValidatesOnDataErrors=True}" />

<ComboBox IsEnabled="{Binding CanEditNationality}" ItemsSource="{Binding Source={StaticResource cvsCountries}}" DisplayMemberPath="Name" SelectedValuePath="Id" SelectedItem="{Binding Nationality, Mode=TwoWay, UpdateSourceTrigger=LostFocus, ValidatesOnDataErrors=True}" />

使用此设置，每当我更改一个组合框的值时，另一个也会更改。这是预期的行为吗？

With this setup, whenever I change one of the comboboxes' value, the other one changes as well... Is this expected behavior?

（我已经通过使用另一个CollectionViewSource实现了一个修复，我只想知道这是否正常）

(I've implemented a fix by using another CollectionViewSource, I just want to know if this is normal)

推荐答案

这是正常的， CollectionViews 有一个 CurrentItem 如果 ItemsSource 是一个 CollectionView ，则它们会同步，请参阅 IsSynchronizedWithCurrentItem ：

This is normal, CollectionViews have a CurrentItem and if the ItemsSource is a CollectionView they get synchronized, see IsSynchronizedWithCurrentItem:

true 如果 SelectedItem 始终与 ItemCollection ; false ，如果 SelectedItem 从不与当前项同步; null ，如果 SelectedItem 仅当选择器使用时与当前项同步 CollectionView 。默认值为 null 。

true if the SelectedItem is always synchronized with the current item in the ItemCollection; false if the SelectedItem is never synchronized with the current item; null if the SelectedItem is synchronized with the current item only if the Selector uses a CollectionView. The default value is null.

所以你可以手动关闭它，将该属性设置为 false 。

So you can just turn it off manually by setting that property to false.

（顺便说一句，你也可以绑定到 CurrentItem 一个 CollectionView 通过斜线例如人物/名称绑定到在 People 中的当前人物的名称。）

(By the way, you can also bind to the CurrentItem of a CollectionView via a slash. e.g. People/Name binds to the Name property of the current person in People.)

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