Expandable Tree View in xamarin forms

Question

I want to make expandable tree view in android like below screen short Expandable List View . I have tried but i want it with explanation. Hope will get better solution.

Thanks in advance.

Answer 1

There is currently a PR for Xamarin to include this (see here )

For the time being, you can use ExpandableView NuGet which is quite simple:

<expandable:ExpandableView>
    <expandable:ExpandableView.PrimaryView>
        //{YOUR MAIN VIEW HERE}
    </expandable:ExpandableView.PrimaryView>
    <expandable:ExpandableView.SecondaryViewTemplate>
        <DataTemplate>
            //{YOUR DROP-DOWN MENU TEMPLATE HERE} you can use DataTemplateSelector too
        </DataTemplate>
    </expandable:ExpandableView.SecondaryViewTemplate>
</expandable:ExpandableView>

Answer 2

You can use Xamarin Community Toolkit package:

 xmlns:xct="http://xamarin.com/schemas/2020/toolkit"

You have possibility to define a header, nest several expander, define the View as a Content or using a DataTemplate, define animations ( ExpandAnimationEasing , CollapseAnimationEasing )...

<xct:Expander IsEnabled="{Binding IsEnabled}" ExpandAnimationEasing="{x:Static Easing.CubicIn}"
                                             CollapseAnimationEasing="{x:Static Easing.CubicOut}">
    <xct:Expander.Header>
        <Label Text="Nested expander" FontSize="30" FontAttributes="Bold"/>
    </xct:Expander.Header>
    <xct:Expander.ContentTemplate>
        <DataTemplate>
            <StackLayout Spacing="0" Margin="10" Padding="1" BackgroundColor="Black">
                <BoxView HeightRequest="50" Color="White" />
                <BoxView HeightRequest="50" Color="Red" />
                <BoxView HeightRequest="50" Color="White" />
            </StackLayout>
        </DataTemplate>
    </xct:Expander.ContentTemplate>
</xct:Expander>

Note from the documentation

The Expander control is known to show unwanted behavior when used in a ListView or CollectionView. At this time we recommend not using a Expander in one of these controls.

Resource

Nuget: https://www.nuget.org/packages/Xamarin.CommunityToolkit

Documentation: https://docs.microsoft.com/en-us/xamarin/community-toolkit/views/expander

Repo: https://github.com/xamarin/XamarinCommunityToolkit