private async void StopTrack_Click(object sender, RoutedEventArgs e)
{
MessageDialog messageDialog = new MessageDialog("停止tracking");
await messageDialog.ShowAsync();
trackingGeolocator.Stop();
trackingGeolocator.PositionChanged -= aMapGeolocator_PositionChanged;
}
private void OnMapUnloaded(object sender, RoutedEventArgs e)
{
if (geolocator != null)
{
geolocator.PositionChanged -= OnPositionChanged;
geolocator.Stop();
}
}