[Wasm] ListView GroupStyle.HeaderTemplate not rendering

[bricelam]

Current behavior

Group headers are not shown on Web Assembly.

Expected behavior

They should render the same as the do on Android...

...or UWP.

How to reproduce it (as minimally and precisely as possible)

I'm using this in my view...

<Page.Resources>
  <CollectionViewSource x:Name="FruitsCVS" Source="{x:Bind Fruits}" IsSourceGrouped="True" />
</Page.Resources>

<ListView ItemsSource="{x:Bind FruitsCVS.View}">
  <ListView.GroupStyle>
    <GroupStyle>
      <GroupStyle.HeaderTemplate>
        <DataTemplate>
          <TextBlock Text="{Binding Key}" />
        </DataTemplate>
      </GroupStyle.HeaderTemplate>
    </GroupStyle>
  </ListView.GroupStyle>
</ListView>

...and this in my code-behind.

public IEnumerable<IGrouping<string, string>> Fruits { get; }
    = new[] { "Apple", "Apricot", "Banana" }
        .GroupBy(f => f.Substring(0, 1))
        .OrderBy(g => g.Key);

[jeromelaban]

Thanks for the report! This is actually an issue tracked here: #234. @dr1rrb may have some more information to provide here as a workaround using ItemsRepeater.

[dr1rrb]

Well a solution would indeed be to use the ItemsRepeater. For grouping, you just have to nest ItemsRepeaters eg:

<Page.Resources>
  <DataTemplate x:Key="FruitTemplate">
    <TextBlock Text="{Binding}" />
  </DataTemplate>
</Page.Resources>

<ScrollViewer>
  <ItemsRepeater ItemsSource="{x:Bind FruitsCVS.View}">
    <ItemsRepeater.ItemTemplate>
      <DataTemplate>
        <StackPanel>
          <TextBlock Text="{Binding Key}" />
          <ItemsRepeater ItemsSource="{Binding}" ItemTemplate="{StaticResource FruitTemplate}">
        </StackPanel>
      </DataTemplate>
    </ItemsRepeater.ItemTemplate>
  </ItemsRepeater>
</ScrollViewer>

[dr1rrb]

Here in live: https://playground.platform.uno/#92bb9f16

[KWodarczyk]

Same issue with GridView, which is more complex control than ListView so not sure using nested repeaters will do the job, any idea when this be fixed ? It works fine on Windows Apps Sdk target but not in Web Assembly

[MartinZikmund]

Is the use of ItemsRepeater a valid solution for you?

[KWodarczyk]

It's ok for time being