//Quan ly loai benh
private void btnAddSickness_Click(object sender, RoutedEventArgs e)
{
AddSickness addSick = new AddSickness(null);
addSick.ShowDialog();
List <Sickness> listSickness = DataManager.getInstance().getAllSickness();
sicknessDataGrid.DataContext = listSickness;
}
private void btnEditSickness_Click(object sender, RoutedEventArgs e)
{
Sickness sick = sicknessDataGrid.SelectedItem as Sickness;
AddSickness editSick = new AddSickness(sick);
editSick.ShowDialog();
List <Sickness> listSickness = DataManager.getInstance().getAllSickness();
sicknessDataGrid.DataContext = listSickness;
}