UserDefaults:Default UserDefaults扩展框架

用户默认值 建置状态 的iOS 苹果系统 watchOS 操作系统 用法 定义静态密钥以便于访问UserDefaults中存储的数据 extension DefaultsKeys { static let key = DefaultsKey < String> ( " key " ) static let number = DefaultsKey < Double> ( " number " ) static let condition = DefaultsKey < Bool> ( " condition " ) // eg. struct SomeCodable : Codeable { ... } static let codeable = DefaultsKey < SomeCodable> ( " somecodeable " ) } 写入用户默认