binding CarouselView.Loop does not listen to property changed events

[Qythyx]

Description

If you have a CarouselView and bind the Loop property to a property in you view model, it does not properly detect if that value changes.

Steps to Reproduce

1. Create a XAML file with a CarouselView in it.
2. Bind the Loop property like Loop="{Binding LoopCarousel}".
3. In the view model, have the bound property change its value at some point.

Expected Behavior

When the bound property's value changes, the CarouselView should adjust.

Actual Behavior

It does not detect the changed value.

Basic Information

• Version with issue: Xamarin.Forms 5.0.0.1931
• Last known good version: n/a
• Platform Target Frameworks: iOS and Android (didn't test others)

Environment

Show/Hide Visual Studio info

``` === Visual Studio Community 2019 for Mac === Version 8.8.7 (build 18) Installation UUID: 31691d7a-f24d-4bdf-8e0f-8ea9a4f8380a GTK+ 2.24.23 (Raleigh theme) Xamarin.Mac 6.18.0.23 (d16-6 / 088c73638) Package version: 612000113 === Mono Framework MDK === Runtime: Mono 6.12.0.113 (2020-02/4fdfb5b1fd5) (64-bit) Package version: 612000113 === Roslyn (Language Service) === 3.8.0-5.20519.18+4c195c3ac1974edcefa76774d7a59a2350ec55fa === NuGet === Version: 5.8.0.6860 === .NET Core SDK === SDK: /usr/local/share/dotnet/sdk/5.0.102/Sdks SDK Versions: 5.0.102 5.0.101 5.0.100 3.1.405 3.1.404 MSBuild SDKs: /Applications/Visual Studio.app/Contents/Resources/lib/monodevelop/bin/MSBuild/Current/bin/Sdks === .NET Core Runtime === Runtime: /usr/local/share/dotnet/dotnet Runtime Versions: 5.0.2 5.0.1 5.0.0 3.1.11 3.1.10 === .NET Core 3.1 SDK === SDK: 3.1.405 === Xamarin.Profiler === Version: 1.6.15.68 Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler === Updater === Version: 11 === Apple Developer Tools === Xcode 12.4 (17801) Build 12D4e === Xamarin.Mac === Version: 7.2.0.3 (Visual Studio Community) Hash: c51fabee8 Branch: xcode12.3 Build date: 2020-12-10 21:05:04-0500 === Xamarin.iOS === Version: 14.8.0.3 (Visual Studio Community) Hash: c51fabee8 Branch: xcode12.3 Build date: 2020-12-10 21:05:05-0500 === Xamarin Designer === Version: 16.8.0.510 Hash: 44e3f3ce9 Branch: remotes/origin/d16-8 Build date: 2020-12-10 00:06:14 UTC === Xamarin.Android === Version: 11.1.0.26 (Visual Studio Community) Commit: xamarin-android/d16-8/a36ce73 Android SDK: /Users/rainer/Library/Developer/Xamarin/android-sdk-macosx Supported Android versions: None installed SDK Tools Version: 26.1.1 SDK Platform Tools Version: 30.0.4 SDK Build Tools Version: 29.0.3 Build Information: Mono: 5e9cb6d Java.Interop: xamarin/java.interop/d16-8@79d9533 ProGuard: Guardsquare/proguard/proguard6.2.2@ebe9000 SQLite: xamarin/sqlite/3.32.1@1a3276b Xamarin.Android Tools: xamarin/xamarin-android-tools/d16-8@2fb1cbc === Microsoft OpenJDK for Mobile === Java SDK: /Users/rainer/Library/Developer/Xamarin/jdk/microsoft_dist_openjdk_1.8.0.25 1.8.0-25 Android Designer EPL code available here: https://github.com/xamarin/AndroidDesigner.EPL === Android SDK Manager === Version: 16.8.0.32 Hash: 01a7774 Branch: remotes/origin/d16-8 Build date: 2021-01-14 00:34:58 UTC === Android Device Manager === Version: 16.8.0.46 Hash: 0a81419 Branch: remotes/origin/d16-8 Build date: 2021-01-14 00:35:22 UTC === Build Information === Release ID: 808070018 Git revision: 0f6def3c0ff5f9cee230e65718561cb41c8eedc0 Build date: 2021-01-29 08:24:09-05 Build branch: release-8.8 Xamarin extensions: 0f6def3c0ff5f9cee230e65718561cb41c8eedc0 === Operating System === Mac OS X 10.16.0 Darwin 20.3.0 Darwin Kernel Version 20.3.0 Thu Jan 21 00:07:06 PST 2021 root:xnu-7195.81.3~1/RELEASE_X86_64 x86_64 === Enabled user installed extensions === Code Coverage 1.1 XAML Styler 2.0.1```

Workaround

In my XAML code behind file I listen to the view model's PropertyChanged event and do this:

// This is needed because CarouselView.Loop does not seem to listen to the binding change correctly.
private void OffersPage_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
    if(e.PropertyName == nameof(OffersViewModel.LoopCarousel)) {
        carousel.Loop = ((OffersViewModel)BindingContext).LoopCarousel;
    }
}

[jsuarezruiz]

Attached repro sample: Issue13706.zip

[Painwraith]

Problem still persists.