Long tap and drop pin in xamarin forms maps - xamarin.forms

Question

I used Xamarin.Forms.Maps nuget package and displayed map on the device. I am able to show the pin on external button tap with the help of following code, but unable to achieve same on map tap to drop a pin on a specific location.
public void addPin(double latitude, double longitude, string labelName)
{
Position position = new Position(latitude, longitude);
_assignedPin = new Pin
{
Type = PinType.Place,
Position = position,
Label = labelName,
Address = "custom detail info"
};
map.Pins.Add(_assignedPin);
}
I followed this blog to get lat long on map, but map does not display the pin on the map.

Answer 1

We need to add the code in renderer itself to drop pin using xamarin.forms.maps
In Android: Renderer class:
private void googleMap_MapClick(object sender, GoogleMap.MapClickEventArgs e)
{
Map.Pins.Add(new Pin
{
Label = "Pin from tap",
Position = new Position(e.Point.Latitude, e.Point.Longitude))
}
}
And in iOS Renderer class:
[assembly: ExportRenderer(typeof(ExtMap), typeof(ExtMapRenderer))]
namespace Xamarin.iOS.CustomRenderers
{
/// <summary>
/// Renderer for the xamarin ios map control
/// </summary>
public class ExtMapRenderer : MapRenderer
{
private readonly UITapGestureRecognizer _tapRecogniser;
public ExtMapRenderer()
{
_tapRecogniser = new UITapGestureRecognizer(OnTap)
{
NumberOfTapsRequired = 1,
NumberOfTouchesRequired = 1
};
}
protected override IMKAnnotation CreateAnnotation(Pin pin)
{
return base.CreateAnnotation(pin);
}
class BasicMapAnnotation : MKAnnotation
{
CLLocationCoordinate2D coord;
string title, subtitle;
public override CLLocationCoordinate2D Coordinate { get { return coord; } }
public override void SetCoordinate(CLLocationCoordinate2D value)
{
coord = value;
}
public override string Title { get { return title; } }
public override string Subtitle { get { return subtitle; } }
public BasicMapAnnotation(CLLocationCoordinate2D coordinate, string title, string subtitle)
{
this.coord = coordinate;
this.title = title;
this.subtitle = subtitle;
}
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
}
private async void OnTap(UITapGestureRecognizer recognizer)
{
var cgPoint = recognizer.LocationInView(Control);
var nativeMap = Control as MKMapView;
var location = ((MKMapView)Control).ConvertPoint(cgPoint, Control);
((ExtMap)Element).OnTap(new Position(location.Latitude, location.Longitude));
try
{
var lat = location.Latitude;
var lon = location.Longitude;
var placemarks = await Geocoding.GetPlacemarksAsync(lat, lon);
var placemark = placemarks?.FirstOrDefault();
if (placemark != null)
{
var geocodeAddress =
$"AdminArea: {placemark.AdminArea}\n" +
$"CountryCode: {placemark.CountryCode}\n" +
$"CountryName: {placemark.CountryName}\n" +
$"FeatureName: {placemark.FeatureName}\n" +
$"Locality: {placemark.Locality}\n" +
$"PostalCode: {placemark.PostalCode}\n" +
$"SubAdminArea: {placemark.SubAdminArea}\n" +
$"SubLocality: {placemark.SubLocality}\n" +
$"SubThoroughfare: {placemark.SubThoroughfare}\n" +
$"Thoroughfare: {placemark.Thoroughfare}\n";
Console.WriteLine(geocodeAddress);
var annotation = new BasicMapAnnotation(new CLLocationCoordinate2D(lat, lon), placemark.Thoroughfare, placemark.SubThoroughfare);
nativeMap.AddAnnotation(annotation);
}
}
catch (FeatureNotSupportedException fnsEx)
{
// Feature not supported on device
Console.WriteLine(fnsEx);
}
catch (Exception ex)
{
// Handle exception that may have occurred in geocoding
Console.WriteLine(ex);
}
}
protected override void OnElementChanged(ElementChangedEventArgs<View> e)
{
if (Control != null)
Control.RemoveGestureRecognizer(_tapRecogniser);
base.OnElementChanged(e);
if (Control != null)
Control.AddGestureRecognizer(_tapRecogniser);
}
}
}