xamarin form UI thread

gistfile1.txt

var syncContext = SynchronizationContext.Current; // UI Thread

Task.Run(() => 
{
    LatLon result = HeavyFunction(); // Run synchronously on background
    syncContext.Post(state =>
    {
        // Run on UI Thread
        map.Pins.Add(new Pin(…)); // Add pin or few pins
    }, null);
});