Collection View Header and Empty View not showing on Android when ItemSource is null

[3steve3]

Description

If the data the CollectionView is bound to is null, then CollectionView.Header and CollectionView.Empty View is not visible. This issue was also tested on the Windows version and the bug does not appear.
A sample of the issue can be found here https://github.com/3steve3/EmptyCollectionViewBug

Steps to Reproduce

1. Create a new .Net Maui project
2. Create a viewmodel for the view
3. Create a Collection View in the View.
4. Bind the Collection View item source to null variable, CollectionView.Header and CollectionView.EmptyView will not be visible on Android.

Version with bug

6.0.400

Last version that worked well

Unknown/Other

Affected platforms

Android

Affected platform versions

Android 12

Did you find any workaround?

No

Relevant log output

No response

[danielftz]

ETA on the fix?

[ghost]

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.

[99067718]

I'm pretty sure the header is the problem in your case.
It should be fixed after you remove the header.

[3steve3]

My application needs to have things in a header (if using a collection view) because stacking content and a collection view results in incorrect scroll height.

[Syed-RI]

cc @davidortinau @jfversluis @PureWeen . This is a basic requirement thats failing us now. Can you please assign resources in this issue please? I know you guys are working hard and really appreciate the work :) Thank you!

[3steve3]

This is the general workaround I came up with until the bug is fixed

<ScrollView>
    <StackLayout>
        This is where the header elements would be
    
      <VerticalStackLayout BindableLayout.ItemsSource="{Binding mySource}">
          <BindableLayout.ItemTemplate>
              <DataTemplate x:DataType="model:MyModel">
                  the bindable content here
              </DataTemplate>
          </BindableLayout.ItemTemplate>
      </VerticalStackLayout>
  </StackLayout>
</ScrollView>

[AlexeyStarkov]

CarouselView has the same issue: Empty view doesn't work on Android whether the source collection is null or empty.

[BurkusCat]

To confirm for CollectionView: an empty ObservableCollection does not show the empty view on Android for me.

[XamlTest]

Verified this on Visual Studio Enterprise 17.7.0 Preview 1.0. Repro on Android 13.0 with below Project:
8934.zip

Android: CollectionView.Header and CollectionView.EmptyView is not visible.

Windows: CollectionView.Header is not visible, CollectionView.EmptyView is visible.

[HobDev]

The empty view only shows up in collectionview if it is set to a string., Facing same issue on Windows too.

[hartez]

#11763 Fixes part of this issue; with that fix applied, the EmptyView will show up as long as there is no header or footer specified.

If a header and/or footer are specified, grouping is not enabled, and the items source does not implement INotifyCollectionChanged, then an empty/null ItemsSource will cause the EmptyView, the Header, and the Footer to disappear. Working on a PR for that right now.

[PureWeen]

#15886