[Bug][iOS] TapGesture in Shell does not work in iOS(Xamarin.Forms).

[GnanaPriyaNamasivayam]

Description

Added TapGesture for View loaded inside Shell.ItemTemplate. Its not working only on iOS 14.1. Last checked iOS version 13.3 worked fine and also Android too works properly.

My app's Xamarin Forms : v4.7.0.1179

Steps to Reproduce

1. Added Xaml for reference view.
2. Use them and hook viewmodel command for one of the Item (LogOut- one of template selector item)loaded inside Shell.ItemTemplate.
3. ViewModel command does not fire for 14.1.

Expected Behavior

Gesture's ViewModel command should fire in iOS 14.1 version.

Actual Behavior

Gesture's ViewModel command not firing in iOS 14.1 version.

Basic Information

• Version with issue: iOS 14.1 and My Xamarin Forms version : 4.7.0.1179
• Last known good version: iOS 13.3 (At that also used same Xamarin Forms vesion)
• IDE:
• Platform Target Frameworks:
  • iOS: 14.1 and please find below iOS platform details for your reference.
    === Visual Studio Community 2019 for Mac ===

Version 8.7.9 (build 9)
Installation UUID: 4016c3dc-d19e-4ab2-aac0-b84d621a8566
GTK+ 2.24.23 (Raleigh theme)
Xamarin.Mac 6.18.0.23 (d16-6 / 088c73638)

Package version: 612000093

=== Mono Framework MDK ===

Runtime:
Mono 6.12.0.93 (2020-02/620cf538206) (64-bit)
Package version: 612000093

=== Roslyn (Language Service) ===

3.7.0-6.20427.1+18ede13943b0bfae1b44ef078b2f3923159bcd32

=== Xamarin Designer ===

Version: 16.7.0.495
Hash: 03d50a221
Branch: remotes/origin/d16-7-vsmac
Build date: 2020-08-28 13:12:52 UTC

=== NuGet ===

Version: 5.7.0.6702

=== .NET Core SDK ===

SDK: /usr/local/share/dotnet/sdk/3.1.403/Sdks
SDK Versions:
3.1.403
3.1.200
3.1.101
MSBuild SDKs: /Library/Frameworks/Mono.framework/Versions/6.12.0/lib/mono/msbuild/Current/bin/Sdks

=== .NET Core Runtime ===

Runtime: /usr/local/share/dotnet/dotnet
Runtime Versions:
3.1.9
3.1.2
3.1.1
2.1.23
2.1.17
2.1.16
2.1.15

=== Xamarin.Profiler ===

Version: 1.6.13.11
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

=== Updater ===

Version: 11

=== Apple Developer Tools ===

Xcode 12.1 (17222)
Build 12A7403

=== Xamarin.Android ===

Version: 11.0.2.0 (Visual Studio Community)
Commit: xamarin-android/d16-7/025fde9
Android SDK: /Users/macmini1/Library/Android/sdk
Supported Android versions:
6.0 (API level 23)
8.0 (API level 26)
8.1 (API level 27)

SDK Tools Version: 26.1.1
SDK Platform Tools Version: 29.0.5
SDK Build Tools Version: 29.0.2

Build Information:
Mono: 83105ba
Java.Interop: xamarin/java.interop/d16-7@1f3388a
ProGuard: Guardsquare/proguard@ebe9000
SQLite: xamarin/sqlite@1a3276b
Xamarin.Android Tools: xamarin/xamarin-android-tools/d16-7@017078f

=== Microsoft OpenJDK for Mobile ===

Java SDK: /Users/macmini1/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: 16.7.0.13
Hash: 8380518
Branch: remotes/origin/d16-7~2
Build date: 2020-09-16 05:12:24 UTC

=== Android Device Manager ===

Version: 16.7.0.24
Hash: bb090a3
Branch: remotes/origin/d16-7
Build date: 2020-09-16 05:12:46 UTC

=== Xamarin.Mac ===

Xamarin.Mac not installed. Can't find /Library/Frameworks/Xamarin.Mac.framework/Versions/Current/Version.

=== Xamarin.iOS ===

Version: 14.2.0.12 (Visual Studio Community)
Hash: e0ce49680
Branch: xcode12.1
Build date: 2020-10-20 09:52:06-0400

=== Build Information ===

Release ID: 807090009
Git revision: d29d54665a1fc79986687a540a7a4676f97ad3da
Build date: 2020-10-21 15:05:18-04
Build branch: release-8.7
Xamarin extensions: d29d54665a1fc79986687a540a7a4676f97ad3da

=== Operating System ===

Mac OS X 10.15.7
Darwin 19.6.0 Darwin Kernel Version 19.6.0
Mon Aug 31 22:12:52 PDT 2020
root:xnu-6153.141.2~1/RELEASE_X86_64 x86_64

• Nuget Packages:
• Affected Devices: IOS 14.1

Screenshots - Sample view

Reproduction Link

<controls:ShellExtended x:Class="Alden.One.Client.Dashboard.Views.DashboardPage"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:controls="clr-namespace:Alden.One.Client.Common.Presentation.Controls;assembly=Alden.One.Client.Common.Presentation"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:iOsSpecific="clr-namespace:Xamarin.Forms.PlatformConfiguration.iOSSpecific;assembly=Xamarin.Forms.Core"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:views="clr-namespace:Alden.One.Client.Dashboard.Views;assembly=Alden.One.Client.Dashboard.Views"
x:Name="ShellExtended"
Title="Dashboard"
iOsSpecific:Page.UseSafeArea="true"
BackgroundColor="#4B5B51"
DetailItems="{Binding DetailItemsList}"
FlyoutBackgroundColor="{StaticResource White}"
mc:Ignorable="d">

<controls:ShellExtended.Resources>
    <ResourceDictionary>

        <Style TargetType="Grid">
            <Setter Property="RowSpacing" Value="0" />
            <Setter Property="ColumnSpacing" Value="0" />

        </Style>

        <Style x:Key="FormDivider" TargetType="BoxView">
            <Setter Property="HeightRequest" Value="0.4" />
            <Setter Property="HorizontalOptions" Value="FillAndExpand" />
            <Setter Property="Color" Value="Gray" />
        </Style>

        <DataTemplate x:Key="LogoutTemplate">
            <StackLayout >
                <Grid Margin="0,10">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="0.2*" />
                        <ColumnDefinition Width="0.8*" />
                    </Grid.ColumnDefinitions>
                    <Image Margin="10"
                       Aspect="AspectFit"
                       Source="menu_logout.png" />
                    <Label Grid.Column="1"
                       FontSize="Medium"
                       LineBreakMode="WordWrap"
                       MaxLines="1"
                       Text="{Binding Title}"
                       TextColor="{StaticResource AccentColor}"
                       VerticalTextAlignment="Center" />

                </Grid>
                <BoxView HeightRequest="5"/>
                <StackLayout.GestureRecognizers>
                    <TapGestureRecognizer Command="{Binding Source={x:Reference ShellExtended}, Path=BindingContext.LogoutCommand}" Tapped="TapGestureRecognizer_OnTapped" />
                </StackLayout.GestureRecognizers>
            </StackLayout>


        </DataTemplate>

        <DataTemplate x:Key="SelectableItemTemplate">
            <StackLayout>
                <Grid Margin="0,10">

                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="0.2*" />
                        <ColumnDefinition Width="0.5*" />
                        <ColumnDefinition Width="0.3*" />
                    </Grid.ColumnDefinitions>

                    <Image Margin="10" Source="{Binding FlyoutIcon}" />

                    <Label Grid.Column="1"
                       FontSize="Medium"
                       Text="{Binding Title}"
                       TextColor="{StaticResource AccentColor}"
                       VerticalTextAlignment="Center" />

                    <Switch Grid.Column="2" IsToggled="{Binding Source={x:Reference ShellExtended}, Path=BindingContext.IsOffline}" />
                    <Grid.GestureRecognizers>
                        <TapGestureRecognizer Command="{Binding Source={x:Reference ShellExtended}, Path=BindingContext.GoOfflineCommand}" Tapped="TapGestureRecognizer_OnTapped" />
                    </Grid.GestureRecognizers>

                </Grid>
                <BoxView HeightRequest="5" />

            </StackLayout>
        </DataTemplate>


        <DataTemplate x:Key="OtherTemplate">
            <StackLayout>
                <Grid Margin="0,10">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="0.2*" />
                    <ColumnDefinition Width="0.8*" />
                </Grid.ColumnDefinitions>
                <Image Margin="10" Source="{Binding FlyoutIcon}" />
                <Label Grid.Column="1"
                       FontSize="Medium"
                       Text="{Binding Title}"
                       TextColor="{StaticResource AccentColor}"
                       VerticalTextAlignment="Center" />
            </Grid>
                <BoxView HeightRequest="5" />

            </StackLayout>
        </DataTemplate>

    </ResourceDictionary>
</controls:ShellExtended.Resources>

<controls:ShellExtended.ItemTemplate>
    <views:FlyOutItemTemplateSelector LogOutFeatureTileTemplate="{StaticResource LogoutTemplate}"
                                      OtherTileTemplate="{StaticResource OtherTemplate}"
                                      SelectableFeatureTileTemplate="{StaticResource SelectableItemTemplate}" />
</controls:ShellExtended.ItemTemplate>

<controls:ShellExtended.FlyoutHeader>
    <Grid Margin="0,10"
          BackgroundColor="{StaticResource White}"
          HeightRequest="75"
          VerticalOptions="CenterAndExpand">

        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="25*" />
            <ColumnDefinition Width="75*" />
        </Grid.ColumnDefinitions>

        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>

        <Image Grid.Row="0"
               Grid.RowSpan="2"
               Grid.Column="0"
               Margin="10"
               Source="menu_profile.png" />

        <Label Grid.Row="0"
               Grid.Column="1"
               FontSize="Small"
               MaxLines="1"
               Text="{Binding UserName}"
               TextColor="{StaticResource AccentColor}"
               VerticalOptions="EndAndExpand"
               VerticalTextAlignment="Center" />

        <Label Grid.Row="1"
               Grid.Column="1"
               FontSize="Small"
               MaxLines="1"
               Text="{Binding Email}"
               TextColor="{StaticResource AccentColor}"
               VerticalOptions="StartAndExpand"
               VerticalTextAlignment="Center" />

    </Grid>
</controls:ShellExtended.FlyoutHeader>

<!--  Adding a blank page to cheat the shell core since it checks for default added item we are handling it in the extended shell element :-)  -->
<ContentPage />

</controls:ShellExtended>

Workaround

No .

[rachelkang]

Hi, @GnanaPriyaNamasivayam - thanks for submitting this issue! Unfortunately, I wasn't able to reproduce it :/
Would you mind sharing either this project or a smaller sample project that reproduces the same issue? Thank you :)

[GnanaPriyaNamasivayam]

Hi @rachelkang , Hope this helps.
Uploading ShellSample.zip…

I tried to replicate in documentation sample. You can also use my project xaml in above sample to confirm. Please ensure in iOS 14.0

[jsuarezruiz]

@GnanaPriyaNamasivayam Sorry, it seems that the attached example was not uploaded correctly last time, could you upload it again?

[GnanaPriyaNamasivayam]

@jsuarezruiz / @rachelkang Uploaded sample link : https://easyupload.io/e57utm

If still not replicated in your side then you can use above xaml template in your shell sample.

[PureWeen]

This should be fixed by this PR

#12967