Target-ActionモデルのAPIを使うとき、Actionに指定するメソッドはPrivateにしたいけど、その場合 @objc 付けないと実行時エラーになる。 class MyViewController: UIViewController { override func viewDidLoad() { super.viewDidLoad() navigationItem.leftBarButtonItem = UIBarButtonItem( barButtonSystemItem: UIBarButtonSystemItem.Done, target: self, action: "test" ) } //OK @objc private func test() { println("test") } /* //NG private func test() { println("
![privateメソッドをSelectorとして指定する場合は@objcが必要 - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/6519cf28d36872ca3bf6e386284b55e783166e80/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-9f5428127621718a910c8b63951390ad.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTkxNiZoPTMzNiZ0eHQ9cHJpdmF0ZSVFMyU4MyVBMSVFMyU4MiVCRCVFMyU4MyU4MyVFMyU4MyU4OSVFMyU4MiU5MlNlbGVjdG9yJUUzJTgxJUE4JUUzJTgxJTk3JUUzJTgxJUE2JUU2JThDJTg3JUU1JUFFJTlBJUUzJTgxJTk5JUUzJTgyJThCJUU1JUEwJUI0JUU1JTkwJTg4JUUzJTgxJUFGJTQwb2JqYyVFMyU4MSU4QyVFNSVCRiU4NSVFOCVBNiU4MSZ0eHQtY29sb3I9JTIzMjEyMTIxJnR4dC1mb250PUhpcmFnaW5vJTIwU2FucyUyMFc2JnR4dC1zaXplPTU2JnR4dC1jbGlwPWVsbGlwc2lzJnR4dC1hbGlnbj1sZWZ0JTJDdG9wJnM9NzlhOTU1MmVmMjk1NWJmZDVmNWRiZGZiMmY0NzhmYzY%26mark-x%3D142%26mark-y%3D112%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTYxNiZ0eHQ9JTQwa2VubWF6JnR4dC1jb2xvcj0lMjMyMTIxMjEmdHh0LWZvbnQ9SGlyYWdpbm8lMjBTYW5zJTIwVzYmdHh0LXNpemU9MzYmdHh0LWFsaWduPWxlZnQlMkN0b3Amcz1lOWM2NDk4YmQxMmViZThmNTVlOTJlYTQ5Nzg5ZDFiZA%26blend-x%3D142%26blend-y%3D491%26blend-mode%3Dnormal%26s%3Db444173e7e6d93d581a8f477fd91f9b7)