How do I to manipulate StackLayout to visible true or false? - xamarin

Question

I am trying to manipulate a stacklayout but I cannot getting its name on controller to change it visible or not. How can I do that, is it works on Xamarin ?
Trying
<ContentPage.Content>
<StackLayout HorizontalOptions="FillAndExpand" Padding="2">
<StackLayout HorizontalOptions="FillAndExpand">
<Label Text="Compre agora seu número da sorte"
FontSize="Small"
TextColor="Gray"
FontAttributes="Bold"
HorizontalOptions="CenterAndExpand"
/>
</StackLayout>
<StackLayout HorizontalOptions="FillAndExpand">
<Label Text="Concurso" FontAttributes="Bold"></Label>
<Label x:Name="idConcurso"></Label>
<Label Text="Prêmio" FontAttributes="Bold"></Label>
<Label x:Name="premioNome"></Label>
</StackLayout>
<StackLayout HorizontalOptions="FillAndExpand">
<ListView x:Name="GridNumerosDaSorte"
SeparatorVisibility="Default"
HasUnevenRows="true"
ItemAppearing="OnItemAppearing"
>
<ListView.Header>
<StackLayout Orientation="Horizontal" BackgroundColor="#335D3B">
<Label Text="Nº da Sorte" TextColor="#FFF" HorizontalOptions="StartAndExpand" ></Label>
<Label Text="Valor(R$)" TextColor="#FFF" HorizontalOptions="CenterAndExpand" ></Label>
<Label Text="Controle" TextColor="#335D3B" HorizontalOptions="EndAndExpand" ></Label>
</StackLayout>
</ListView.Header>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal" Margin="0,10,0,0">
<Label Text="{Binding numero}" HorizontalOptions="StartAndExpand"></Label>
<Label Text="{Binding valor, StringFormat='{}{0:N}'}" HorizontalOptions="EndAndExpand" ></Label>
<Button Text="Comprar" Clicked="OnComprarClick" CommandParameter="{Binding .}" HorizontalOptions="EndAndExpand" BackgroundColor="Orange"></Button>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
<StackLayout x:Name="FooterPanel" HorizontalOptions="FillAndExpand" IsVisible="False">
<Label Text="text 1" HorizontalOptions="StartAndExpand"></Label>
<Label Text="text 2" HorizontalOptions="CenterAndExpand"></Label>
<Label Text="text 3" HorizontalOptions="EndAndExpand"></Label>
</StackLayout>
</StackLayout>
</ContentPage.Content>
Controller
//x:Name does not appear on controller, it does not works
FooterPanel.isVisible = true;