Why doesn't the Image Indicator Template update its source when the Visual State is set to 'Selected'?

[cris-m]

I was trying to work with CarouselView and IndicatorView using image template. IndicatorTemplate doesnot change the Image source when the VisualState is selected.

public class Test 
{
    public string Title { get; set; }
    public string SubTitle { get; set; }
    public string Description { get; set; }
}
class TestPage : Component
{
    public List<Test> tests;
    private MauiControls.CarouselView? _carouselView;
    public TestPage()
    {
        tests = new List<Test>()
        {
            new Test 
            {
                Title = "Lorem Ipsum Dolor Sit Amet",
                SubTitle = "Consectetur Adipiscing Elit",
                Description = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed in libero non quam accumsan sodales vel vel nunc."
            },
            new Test 
            {
                Title = "Praesent Euismod Tristique",
                SubTitle = "Vestibulum Fringilla Egestas",
                Description = "Praesent euismod tristique vestibulum. Vivamus vestibulum justo in massa aliquam, id facilisis odio feugiat. Duis euismod massa id elit imperdiet."
            },
            new Test 
            {
                Title = "Aliquam Erat Volutpat",
                SubTitle = "Aenean Feugiat In Mollis",
                Description = "Aliquam erat volutpat. Aenean feugiat in mollis ac. Nullam eget justo ut orci dictum auctor."
            },
            new Test 
            {
                Title = "Suspendisse Tincidunt",
                SubTitle = "Faucibus Ligula Quis",
                Description = "Suspendisse tincidunt, arcu eget auctor efficitur, nulla justo tristique neque, et fermentum orci ante eget nunc."
            },
        };
    }
    public override VisualNode Render()
    {
        return new ContentPage 
        {
            new VStack 
            {
                new Grid("* 40", "*")
                {
                    new CarouselView(r => _carouselView = r)
                        .HeightRequest(450)
                        .HorizontalScrollBarVisibility(ScrollBarVisibility.Never)
                        .ItemsSource(tests, _=> new Grid("*", "*")
                        {
                            new VStack 
                            {
                                  new Label(_.Title)
                                    .Margin(0,5)
                                    .TextColor(Themes.Current.OnBackground),
                                  new Label(_.SubTitle)
                                    .Margin(0,5)
                                    .TextColor(Themes.Current.OnBackground),
                                 new Label(_.Description)
                                    .Margin(0,8)
                                    .TextColor(Themes.Current.OnBackground)
                            }
                        })
                        .WithAnimation(),

                    new IndicatorView(r =>
                    {
                        if (_carouselView != null)
                        {
                            _carouselView.IndicatorView = r;
                        }
                    })
                    .HCenter()
                    .VCenter()
                    .IndicatorColor(Colors.Transparent)
                    .SelectedIndicatorColor(Colors.Transparent)
                    .IndicatorTemplate(() => new Image("empty.png").WidthRequest(20).HeightRequest(20))
                    .VisualState("CommonStates", "Normal", MauiControls.Image.SourceProperty, "empty.png")
                    .VisualState("CommonStates", "Selected", MauiControls.Image.SourceProperty, "fill.png")
                    .GridRow(1),
                }
            }
            .Padding(8,0)
            .VCenter()
        }
        .BackgroundColor(Themes.Current.Background);
    }
}

Simulator.Screen.Recording.-.iPhone.SE.3rd.generation.-.2023-09-08.at.19.24.08.mp4

[adospace]

I verified the issue but it seems to be a .NET MAUI problem:
dotnet/maui#13343

[adospace]

anyway, this code should work for you too?

public class TestModel
{
    public string? Title { get; set; }
    public string? SubTitle { get; set; }
    public string? Description { get; set; }
}

class CarouselTestPageWithImagesState
{
    public List<TestModel> Models { get; set; } = new();

    public TestModel? SelectedModel { get; set; }

}

class CarouselTestWithImagesPage : Component<CarouselTestPageWithImagesState>
{
    private MauiControls.CarouselView? _carouselView;

    protected override void OnMounted()
    {
        State.Models = new List<TestModel>()
        {
            new TestModel
            {
                Title = "Lorem Ipsum Dolor Sit Amet",
                SubTitle = "Consectetur Adipiscing Elit",
                Description = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed in libero non quam accumsan sodales vel vel nunc."
            },
            new TestModel
            {
                Title = "Praesent Euismod Tristique",
                SubTitle = "Vestibulum Fringilla Egestas",
                Description = "Praesent euismod tristique vestibulum. Vivamus vestibulum justo in massa aliquam, id facilisis odio feugiat. Duis euismod massa id elit imperdiet."
            },
            new TestModel
            {
                Title = "Aliquam Erat Volutpat",
                SubTitle = "Aenean Feugiat In Mollis",
                Description = "Aliquam erat volutpat. Aenean feugiat in mollis ac. Nullam eget justo ut orci dictum auctor."
            },
            new TestModel
            {
                Title = "Suspendisse Tincidunt",
                SubTitle = "Faucibus Ligula Quis",
                Description = "Suspendisse tincidunt, arcu eget auctor efficitur, nulla justo tristique neque, et fermentum orci ante eget nunc."
            },
        };
        
        State.SelectedModel = State.Models.First();

        base.OnMounted();
    }

    public override VisualNode Render()
    {
        return new ContentPage
        {
            new VStack
            {
                new Grid("* 40", "*")
                {
                    new CarouselView(r => _carouselView = r)
                        .HeightRequest(450)
                        .HorizontalScrollBarVisibility(ScrollBarVisibility.Never)
                        .ItemsSource(State.Models, _=> new Grid("*", "*")
                        {
                            new VStack
                            {
                                  new Label(_.Title)
                                    .Margin(0,5),
                                  new Label(_.SubTitle)
                                    .Margin(0,5),
                                 new Label(_.Description)
                                    .Margin(0,8)
                            }
                        })
                        .CurrentItem(() => State.SelectedModel!)
                        .OnCurrentItemChanged((s, args) => SetState(s => s.SelectedModel = (TestModel)args.CurrentItem))
                        ,

                    new HStack(spacing: 5)
                    {
                        State.Models.Select(item => 
                            new Image(State.SelectedModel == item ? "tab_home.png" : "tab_map.png")
                                .WidthRequest(20)
                                .HeightRequest(20)
                                .OnTapped(()=>SetState(s=>s.SelectedModel = item, false))
                            )
                    }
                    .HCenter()
                    .VCenter()
                    .GridRow(1)
                }
            }
            .Padding(8,0)
            .VCenter()
        };
    }
}

[cris-m]

Yeah. it is the perfect solution. Thanks for the help