没有更多上下文，表达类型不明确：.UIApplication.willResignActiveNotification

Question

我遇到了以下几行代码中的表达式类型不明确的问题：

缺乏更多上下文，使表达式类型模糊不清

代码如下：

 NotificationCenter.default.addObserver(self, selector: #selector(willResignActive), name: .UIApplication.willResignActiveNotification , object: nil)
 NotificationCenter.default.addObserver(self, selector: #selector(openedAgain), name: .UIApplication.didBecomeActiveNotification, object: nil)

什么是正确的语法？

- user10813210

Answer 1

在UIApplication.willResignActiveNotification中去掉.。

你的代码应该像这样:

NotificationCenter.default.addObserver(self, selector: #selector(willResignActive), name: UIApplication.willResignActiveNotification , object: nil)

- Gustavo Vollbrecht