void EditExecute()
{
EditStudentWindow window = new EditStudentWindow();
Student editItem = new Student();
editItem.CloneFrom(this.SelectedItem);
EditStudentWindowViewModel vm = new EditStudentWindowViewModel(editItem, window);
window.DataContext = vm;
window.ShowDialog();
OnEditComplete(vm);
}
void AddExecute()
{
EditStudentWindow window = new EditStudentWindow();
EditStudentWindowViewModel vm = new EditStudentWindowViewModel(null, window);
window.DataContext = vm;
window.ShowDialog();
OnEditComplete(vm);
}