public void OnOk(Window win)
 {
     if (this.CurrentViewModel is GoogleHistoryViewModel)
     {
         GoogleHistoryViewModel gh = this.CurrentViewModel as GoogleHistoryViewModel;
         this.m_history = gh.Adapt <GoogleHistory>();
         this.m_history.OnRetrievedDataHandler = History_OnRetrievedData;
         this.m_history.ExecuteAsync();
         this.CurrentViewModel  = new LoadingViewModel();
         this.IsOkButtonVisible = false;
         this.RaisePropertyChanged(null);
     }
     else if (this.CurrentViewModel is LoadingViewModel)
     {
     }
     else if (this.CurrentViewModel is DataResultViewModel)
     {
         this.OnCancel(win);
         DataResultViewModel dvm = this.CurrentViewModel as DataResultViewModel;
         if (ExcelHandler.WriteToRangeHandler != null)
         {
             ExcelHandler.WriteToRangeHandler(dvm.Result, dvm.GH);
         }
     }
 }
        private void History_OnRetrievedData(GoogleHistory gh, object[,] result)
        {
            DataResultViewModel dvm = new DataResultViewModel();

            dvm.GH                    = gh;
            dvm.Result                = result;
            this.CurrentViewModel     = dvm;
            this.IsOkButtonVisible    = true;
            this.IsCancelButonVisible = false;
            this.RaisePropertyChanged(null);
        }