ObservableCollection.CollectionChanged select 工具栏上的 DataTemplate 不正确

Question

我的项目有一个带有 3 个数据模板的工具栏：

  <ToolBar ItemsSource="{Binding ContextActions}" Background="Transparent" ToolBarTray.IsLocked="True">
        <ToolBar.Resources>
            <DataTemplate DataType="{x:Type viewModels:SimpleContextActionViewModel}">
                <Button Command="{Binding ActionCommand}" Style="{StaticResource ToolBarButtonStyle}" ToolTip="{userInterface:Translation Binding={Binding ToolTip}}">
                    <ContentControl Template="{Binding Icon,Converter={StaticResource NameToResourceConverter}}" Margin="5" />
                </Button>
            </DataTemplate>
            <DataTemplate DataType="{x:Type viewModels:SeparatorViewModel}">
                <Rectangle Fill="{StaticResource SeparatorBrush}" Width="1" VerticalAlignment="Stretch" Margin="2,7" />
            </DataTemplate>
            <DataTemplate DataType="{x:Type viewModels:PopupContextActionViewModel}">
                <Grid>
                    <ToggleButton IsChecked="{Binding ElementName=ContextActionPopup, Mode=TwoWay,Path=IsOpen}" Style="{StaticResource ToolBarButtonStyle}"
                                  ToolTip="{userInterface:Translation Binding={Binding ToolTip}}">
                        <ContentControl Template="{Binding Icon, Converter={StaticResource NameToResourceConverter}}" Margin="5" />
                    </ToggleButton>
                    <Popup Name="ContextActionPopup" Height="150" Width="150" StaysOpen="False">
                        <Border BorderBrush="{StaticResource PopupBorderBrush}" BorderThickness="1" Background="White">
                            <ContentControl userInterface:RegionHelper.RegionName="{Binding RegionId}" />
                        </Border>
                    </Popup>
                </Grid>
            </DataTemplate>
        </ToolBar.Resources>
    </ToolBar>

ItemsSource 是一个 ObservableCollection

Answer 1

我不确定这是否适用于您的情况，但您的问题似乎非常类似于：Wiring up CollectionChanged and PropertyChanged (Or : Why do some WPF Bindings not refresh?)

来自 link 的已接受答案：

If you don't provide WPF with a template for a data item (such as the Person objects in your list), it'll default to using the ToString() method to display. That's a member, not a property, and so you get no event notification when the value changes.

If you add DisplayMemberPath="Name" to your listbox, it'll generate a template that binds properly to the Name of your person - which will then update automatically as you'd expect.

您能否将 DisplayMemberPath 应用于工具箱，使其默认情况下不使用 ToString() 进行渲染，而是触发 NotifyPropertyChanged？

Answer 2

我以前见过这种情况发生在工具栏上，当与集合一起使用时，除了构造函数之外的任何地方都会发生变化。

不要在工具栏资源中添加您的数据模板，而是将它们添加到 app.xaml 然后您将看到您的代码将正常工作。试试这个，让我知道它是否仍然无法正常工作

ObservableCollection.CollectionChanged select 工具栏上的 DataTemplate 不正确

ObservableCollection.CollectionChanged does not select the correct DataTemplate on ToolBar

c#

wpf

datatemplate