Custom ContextAction with Xamarin Forms

I using a Xamarin Forms ListView and I want to enable or disable the Context Actions based on a certain binding or in the code behind.

The way I found is to use BindingContextChanged in a ViewCell. I show you an example

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="https://xamarin.com/schemas/2014/forms"
             xmlns:x="https://schemas.microsoft.com/winfx/2009/xaml">
  <ContentPage.Content>
    <StackLayout>
      <ListView x:Name="listDictionaries" 
                ItemsSource="{Binding DictionariesList}" 
                IsVisible="{Binding ShowList}"
                HorizontalOptions="FillAndExpand" 
                VerticalOptions="FillAndExpand" 
                HasUnevenRows="true" 
                IsPullToRefreshEnabled="true" 
                RefreshCommand="{Binding Refresh}" 
                SeparatorVisibility="Default" 
                ItemTapped="OnItemTapped" 
                IsRefreshing="{Binding IsBusy, Mode=OneWay}">
        <ListView.ItemTemplate>
          <DataTemplate>
            <ViewCell BindingContextChanged="OnBindingContextChanged">
              <ViewCell.View>
                <StackLayout>
                  <Grid Padding="10" ColumnSpacing="10">
                    <Grid.RowDefinitions>
                      <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                      <ColumnDefinition Width="Auto" />
                      <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <Label Text="{Binding Name}" FontSize="Large" 
                           Grid.Row="0" Grid.Column="0" />
                    <Label Text="{Binding Description}" FontSize="Small" 
                           Grid.Row="1" Grid.Column="0" />
                  </Grid>
                </StackLayout>
              </ViewCell.View>
            </ViewCell>
          </DataTemplate>
        </ListView.ItemTemplate>
      </ListView>
    </StackLayout>
  </ContentPage.Content>
</ContentPage>

Then you insert in the code the following code:

/// <summary>
/// Called when binding context changed.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="e">The <see cref="EventArgs"/> 
/// instance containing the event data.</param>
private void OnBindingContextChanged(object sender, EventArgs e) {
    base.OnBindingContextChanged();

    if (BindingContext == null)
        return;

    ViewCell theViewCell = ((ViewCell)sender);
    var item = theViewCell.BindingContext as DictionaryModel;
    theViewCell.ContextActions.Clear();

    if (item != null) {
        MenuItem mn = new MenuItem();
        mn.Clicked += Menu_Clicked;
        mn.Text = "Delete";
        mn.IsDestructive = true;
        mn.CommandParameter = item.Id;
        theViewCell.ContextActions.Add(mn);
    }
}

private async void Menu_Clicked(object sender, EventArgs e) {
    var mi = ((MenuItem)sender);
}

Happy coding!