判断UIViewController是使用pop，dismiss返回到上级视图控制器

判断UIViewController是使用pop，dismiss返回到上级视图控制器

@(编程笔记)[iOS开发]

if self.navigationController?.topViewController == self, self.navigationController?.viewControllers.first != self {
    self.navigationController?.popViewController(animated: true)
} else {
    self.dismiss(animated: true, completion: nil)
}