How to notify item selection using MVVM in Xamarin.Forms ListView?

 
<ContentPage xmlns:syncfusion="clr-namespace:Syncfusion.ListView.XForms;assembly=Syncfusion.SfListView.XForms" >
     <ContentPage.Resources>
        <ResourceDictionary>
                  <local:CustomConverter x:Key="EventArgs" />
        </ResourceDictionary>
    </ContentPage.Resources>
    <ContentPage.Content>
        <Grid>
         <syncfusion:SfListView x:Name="listView" ItemsSource="{Binding contactsinfo}">
                <listView:SfListView.Behaviors>
                      <local:EventToCommandBehavior EventName="SelectionChanged" 
                                        Command="{Binding OnSelectionChangedCommand}"
                                        Converter="{StaticResource EventArgs}" />
                </listView:SfListView.Behaviors>
           </syncfusion:SfListView>
        </Grid>
    </ContentPage.Content>
</ContentPage>
 

public Command<object> SelectionChangedCommand
{
    get { return selectionChangedCommand; }
    protected set { selectionChangedCommand = value; }
}
 
public ContactsViewModel()
{
    selectionChangedCommand = new Command<object>(OnSelectionChangedCommand);
    contactsinfo = new ObservableCollection<Contacts>();
}
public void OnSelectionChangedCommand (object obj)
{
    var eventArgs = obj as ItemSelectionChangedEventArgs;
            
    for (int i = 0; i < eventArgs.RemovedItems.Count; i++)
    {
       var item = eventArgs.RemovedItems[i] as Contacts;
       if (item.IsSelected)
       {
          item.IsSelected = false;
          App.Current.MainPage.DisplayAlert("Message", "Item removed from selected item", "ok");
       }
    }
    for (int i = 0; i < eventArgs.AddedItems.Count; i++)
    {
       var item = eventArgs.AddedItems[i] as Contacts;
       if (!item.IsSelected)
       {
           item.IsSelected = true;
           App.Current.MainPage.DisplayAlert("Message", "Item added into selected item", "ok");
       }
     }
}