无法将条形按钮项添加到Xcode中的导航控制器

首先,您需要添加 导航项目 在导航栏中。然后在导航项中添加UIBarButton。

通过编程,您可以添加为:

        let shareBarButtonItem = UIBarButtonItem(barButtonSystemItem: .action, target: self, action: #selector(self.shareClass))

        let downloadBarButtonItem = UIBarButtonItem(image: UIImage(string: UIImage(named: "your_image_name")), style: .plain, target: self, action: #selector(self.downloadClass))

        self.navigationItem.setRightBarButtonItems([shareBarButtonItem, downloadBarButtonItem], animated: true)