1)由控件获取内容:
ListViewItem item = Utilities.GetVisualParent<ListViewItem>(chx);
if (item == null) return;
ListView2.SelectedItems.Clear();
item.IsSelected = true;
Outpatient outpatient = item.Content as Outpatient;

2)
Patientappointment appointment = ListView1.SelectedItem as Patientappointment;