Wrong type in ListDetailsView DetailsTemplate

[loics2]

Hi,

I'm currently working on an app using ListDetailsView, and it mostly works correctly. The only issue I have is when the page is loaded, the ItemsSource is empty and filled by an async method. During this short time, nothing is selected and the NoSelectionContentTemplate is briefly displayed, but it appears that my view model is bound to the DetailsTemplate.

Multiple binding errors appear in the console :

Error: BindingExpression path error: 'Name' property not found on 'MyProject.ParametersViewModel'. BindingExpression: Path='ParameterSet.Name' DataItem='MyProject.Components.ParametersEditor'; target element is 'Windows.UI.Xaml.Controls.TextBox' (Name='null'); target property is 'Text' (type 'String')

Error: BindingExpression path error: 'IsDefault' property not found on 'MyProject.ParametersViewModel'. BindingExpression: Path='ParameterSet.IsDefault' DataItem='MyProject.Components.ParametersEditor'; target element is 'Windows.UI.Xaml.Controls.TextBox' (Name='null'); target property is 'IsEnabled' (type 'Boolean')

...

If I try to set a a DataType to the DetailsTemplate, it just crashes with a cast error showing that my view model is bound.

Here's some the xaml :

<!-- page and stuff... -->
<controls:ListDetailsView
         x:Name="ListViewParameters"
         ItemsSource="{x:Bind ViewModel.ParametersList, Mode=OneWay}"
         SelectedItem="{x:Bind ViewModel.Selected, Mode=TwoWay}"
         CompactModeThresholdWidth="720"
         BorderBrush="Transparent"
         NoSelectionContent="Please select a parameter to view"
         ListPaneBackground="{ThemeResource SystemControlPageBackgroundChromeLowBrush}"
         ListPaneWidth="350"
         SelectionChanged="ListViewParameters_SelectionChanged">

    <controls:ListDetailsView.ItemTemplate>
        <DataTemplate x:DataType="parameters:ParameterSet">
            <!-- item template, works great -->
        </DataTemplate>
    </controls:ListDetailsView.ItemTemplate>

    <controls:ListDetailsView.DetailsTemplate>
        <DataTemplate>
            <ScrollViewer x:Name="ContentScrollViewer">
                <StackPanel x:Name="Details" Margin="{StaticResource MediumLeftMargin}">
                    <!-- this is where my view model is bound when the page is loaded -->
                    <TextBlock Style="{StaticResource TitleTextBlockStyle}"
                              Text="{Binding Name, Mode=OneWay}"
                              x:Name="title"
                              Margin="{StaticResource MediumBottomMargin}"/>
                    <!-- other elements with bindings... -->
                </StackPanel>
            </ScrollViewer>
        </DataTemplate>
   </controls:ListDetailsView.DetailsTemplate>
</controls:ListDetailsView>

How can I avoid having my view model bound to the DetailsTemplate ?

Edit : I just noticed it's the value of the DataContext, which is understandable. But I still want to avoid binding errors.

[Kyaa-dost]

@Sergio0694 is there any workaround to make this work and not receive that error ⬆️ without being confined to DetailsTemplate?

[loics2]

Is that the intended behavior? Why does it need a workaround? I'm fairly new to C# and UWP, so if I made something wrong, I'll change it to something more idiomatic.

Also, it looks like there's not much traffic here, should I rather post a question on StackOverflow?

[Kyaa-dost]

@loics2 Sergio might be able to provide more insight into this issue. Discussion is a new platform many of our community members are not aware of this area yet but please feel free to open StackOverflow as that is highly recommended due to the broader audience.