private bool TryGetElevation(GpsLocation location, out double altitude)
{
var et = new ElevationTile(location);
if (et.Exists())
{
if (et.LoadFromZip())
{
altitude = et.GetElevation(location);
return(true);
}
}
altitude = 0;
return(false);
}
public async System.Threading.Tasks.Task <GpsLocation> GetLocationAsync()
{
try
{
if (AppContextLiveData.Instance.Settings.IsManualLocation)
{
return(AppContextLiveData.Instance.Settings.ManualLocation);
}
if (waitingForResponse)
{
return(null);
}
var request = new GeolocationRequest(GeolocationAccuracy.Best, new TimeSpan(0, 0, 0, 5));
waitingForResponse = true;
Location location = await Geolocation.GetLocationAsync(request);
if (location != null)
{
currentLocation.Latitude = location.Latitude;
currentLocation.Longitude = location.Longitude;
currentLocation.Altitude = location.Altitude.Value;
if (AppContextLiveData.Instance.Settings.AltitudeFromElevationMap)
{
if (_elevationTile == null || !_elevationTile.HasElevation(currentLocation))
{
_elevationTile = null;
var et = new ElevationTile(currentLocation);
if (et.Exists())
{
if (et.LoadFromZip())
{
_elevationTile = et;
}
}
}
if (_elevationTile != null)
{
currentLocation.Altitude = _elevationTile.GetElevation(currentLocation);
}
}
return(currentLocation);
}
return(null);
}
catch (FeatureNotSupportedException ex)
{
throw new Exception($"GPS is not supported. {ex.Message}");
}
catch (FeatureNotEnabledException ex)
{
throw new Exception($"GPS is not enabled. {ex.Message}");
}
catch (PermissionException ex)
{
throw new Exception($"GPS is not allowed. {ex.Message}");
}
catch (Exception ex)
{
throw new Exception($"Error when fetching GPS location. {ex.Message}");
}
finally
{
waitingForResponse = false;
}
}