private void ViewData_Click(object sender, RoutedEventArgs e) { if (_dcpList.SelectedItem == null) { ErrorDialog.Show("Please select a DCP!"); return; } var dcp = (IDataCollectProvider)_dcpList.SelectedItem; try { var win = new CustomDataViewer(dcp.DataViewUI); win.Show(); } catch (NotImplementedException) { ErrorDialog.Show("This DCP not implement shch function"); } }