public async Task <Models.Sponsor> GetSponsorAsync(Guid verenigingId, Guid sponsorId) { if (_cachedSponsors == null) { _cachedSponsors = new ObservableCollection <Sponsor>(); } Sponsor sponsor = null; if (_cachedSponsors != null) { sponsor = _cachedSponsors.SingleOrDefault(s => s.Id == sponsorId); } if (sponsor == null) { sponsor = await _sponsorService.GetSponsorAsync(verenigingId, sponsorId); //if(_cachedSpelers.IndexOf(speler) <0 ) if (_cachedSponsors.Where(s => s.Id == sponsor.Id).Count() == 0) { _cachedSponsors.Add(sponsor); } //RaiseSpelerUpdated(); } return(_cachedSponsors.SingleOrDefault(s => s.Id == sponsorId)); }