Swift implements object archiving

There are several points to note when Swift implements object archiving

• To inherit nscoding, implement two methods

• Extension is a classification, the classification does not allow storage capacity, so the protocol method can not be written in the classification

• The init (coder Decoder:nscoder) function in the protocol overrides the original constructor, so there is at least another Init method in the class

• If you do not specify a key name, the attribute name is used as the key, the base data type, and the key must be specified

class <#className#>: NSObject,NSCoding {    // 至少要有一个 init 方法，否则外部没有办法直接实例化对象    // override init() {}    ///  归档方法    func encodeWithCoder(encoder: NSCoder) {        // TODO    }    ///  解档方法，会覆盖构造函数    required init(coder decoder: NSCoder) {        // TODO    }}

Swift implements object archiving