public ProblemViewModel() { _repoClasses = new RepositoryClasses(); _problemsObs = _repoClasses.ProblemObs; _problemsObs.CollectionChanged += _problemsObs_CollectionChanged; _problemExecuteObs = _repoClasses.ProblemExecuteObs; _problemExecuteObs.CollectionChanged += _problemExecuteObs_CollectionChanged; _settClass = _repoClasses.SettClass; _synthesizer = _repoClasses.Synthesizer; // _timeSumObs = new TimeSummaryObservable(TimePeriodType._day, DateTime.Now); _timeSumObs.AddTimeSummary(_problemsObs, TimePeriodType._day); // _dateForIndicator = DateTime.Now; NearestProblem = NearestProblemSet(_problemsObs[0]); }