/// <summary>
/// Handles the BindingContextChanged event.
/// </summary>
protected override void OnBindingContextChanged()
{
// Remove the event handling from the binding context
if (this.currentBindingContext != null)
{
this.pinsSynchronizer.Dispose();
this.pinsSynchronizer = null;
this.currentBindingContext.Navigation = null;
// Remove events handler
this.MapView.Pins.Clear();
this.currentBindingContext.PropertyChanged -= this.OnPropertyChanged;
this.currentBindingContext.ErrorReported -= this.OnErrorReported;
}
// Set up the event handling from the binding context
this.currentBindingContext = this.BindingContext as MainViewModel;
if (this.currentBindingContext != null)
{
// Set up navigation context
this.currentBindingContext.Navigation = this.Navigation;
// Set up event handlers
this.pinsSynchronizer = new CollectionSynchronizer <MapExPin>(
this.currentBindingContext.Pins,
this.MapView.Pins);
this.currentBindingContext.PropertyChanged += this.OnPropertyChanged;
this.currentBindingContext.ErrorReported += this.OnErrorReported;
// The position is not the default one
if (this.currentBindingContext.UserPosition != default(Position))
{
// Move to the selected position
this.OnPropertyChanged(
this.currentBindingContext,
new PropertyChangedEventArgs(nameof(MainViewModel.UserPosition)));
}
}
// Call the base member
base.OnBindingContextChanged();
}
