xcode 如何将 addTarget 方法更新为 swift 4
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/46392832/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to Update addTarget method to swift 4
提问by Habib Alejalil
when update project code to swift 4 get some error for add.target method how i can fix this error?
当将项目代码更新为 swift 4 时，add.target 方法出现一些错误，我该如何修复此错误？
//swift3
var chatLogController: ChatLogController? {
didSet {
sendButton.addTarget(chatLogController, action: #selector(ChatLogController.handleSend), for: .touchUpInside)
uploadImageView.addGestureRecognizer(UITapGestureRecognizer(target: chatLogController, action: #selector(ChatLogController.handleUploadTap)))
}
}
回答by Rashwan L
The hint message is telling you what to do, add @objbefore declaring your function.
提示消息告诉你要做什么，@obj在声明你的函数之前添加。
@objc func handleSend(_ sender: UIGestureRecognizer){
...
}
The reason is because:
原因是因为：
In Objective-C, a selector is a type that refers to the name of an Objective-C method. In Swift, Objective-C selectors are represented by the
Selectorstructure, and can be constructed using the#selectorexpression. To create a selector for a method that can be called from Objective-C, pass the name of the method, such as#selector(MyViewController.tappedButton(_:)). To construct a selector for a property's Objective-C getter or setter method, pass the property name prefixed by thegetter:orsetter:label, such as#selector(getter: MyViewController.myButton).
在Objective-C 中，选择器是一种引用Objective-C 方法名称的类型。在 Swift 中，Objective-C 选择器由
Selector结构表示，并且可以使用#selector表达式来构造。要为可从 Objective-C 调用的方法创建选择器，请传递该方法的名称，例如#selector(MyViewController.tappedButton(_:)). 要为属性的 Objective-C getter 或 setter 方法构造选择器，请传递以getter:或setter:标签为前缀的属性名称，例如#selector(getter: MyViewController.myButton).
Read more here, at Apples documentation.
在此处阅读更多内容，在 Apples 文档中。
