async private void BuildLRAnalysisSheet() { if (!(LRAnalyzer.RunFIS() is null) && !(LRAnalyzer.RunFOS() is null)) { var derivs = LRAnalyzer.BuildDerivs(); await this.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () => { WaitForLRDerivs.Visibility = Visibility.Collapsed; ToSheet.Visibility = Visibility.Visible; derivs.ToList().ForEach(d => { string desc = ""; d.Value.ForEach(s => desc += s.Item1 + " " + s.Item2 + "\n"); LRDerivs.Add(new DerivViewer { Id = d.Key, Description = desc }); }); }); } }