AnyPlace.MainPage.Picker_SelectionChanged C# (CSharp) Method

        private void Picker_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (_firsttimeSearch)
            {
                Mymap.TileSources.Clear();
                var a = Picker.SelectedItem as string;
                _selectedFloor = a;
                ChangeFloor();

                if (!_selectedFloor.Equals(_floorPoiToNumber))
                    Mymap.MapElements.Clear();
                else
                {
                    if (_polyline != null)
                        if (!Mymap.MapElements.Contains(_polyline))
                            Mymap.MapElements.Add(_polyline);
                }

                if (_routePoi != null)
                    if (_routePoi.pois != null)
                        if (_routePoi.pois.Count > 0)
                            GetRouteOfTheCurrentFloor();

                if (Mymap.Layers.Contains(indoorLayer))
                {
                    Mymap.Layers.Remove(indoorLayer);
                    indoorLayer.Clear();
                    if (_floorPoiFromNumber == _floorPoiToNumber)
                    {
                        if (_selectedFloor == _floorPoiToNumber)
                        {
                            indoorLayer.Add(_overlayFrom);
                            indoorLayer.Add(_overlayTo);
                        }

                    }
                    else
                    {
                        if (_selectedFloor == _floorPoiFromNumber)
                        {
                            indoorLayer.Add(_overlayFrom);
                        }
                        else
                            if (_selectedFloor == _floorPoiToNumber)
                                indoorLayer.Add(_overlayTo);
                    }
                    Mymap.Layers.Add(indoorLayer);
                }
            }
            _firsttimeSearch = true;
        }