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【已解决】swift中给一个对象添加支持print打印出对象的描述信息

对于一个对象:

class PersonItem: ContactItem {     var personType:PersonType     var phoneNumber:String     var email:String     var position:String }

之前打印都是：

print("parsed out: /(newPersonItem.type) /(newPersonItem.personType) /(newPersonItem.name) /(newPersonItem.id)")  gLog.debug("parse out /(personItem.phoneNumber) /(personItem.email) /(personItem.position) /(personItem.headerBkgColor) /(personItem.headerImage) /(personItem.headerImageLarge)")

很是麻烦。

想要去添加支持，使得对于print对象，可以自动打印出对应的基本信息

【解决过程】

1.搜：

swift print object description

What is the Swift equivalent of -[NSObject description]? – Stack Overflow

swift – Getting description like NSObject – Stack Overflow

How can I change the textual representation displayed for a type in Swift? – Stack Overflow

Textual Representation for Classes in Swift – Venkat Peri

2.搜：

swift DebugPrintable

Swifter – Swift 必备 tips

http://swifter.tips/print/

ios – Implementing debugDescription for DebugPrintable in Swift – Stack Overflow

cocoa – Difference between Printable and DebugPrintable in Swift – Stack Overflow

变成：

class ContactItem:NSObject, NSCoding, CustomStringConvertible {     var type:ContactType     // person/group/topic id string     var id:String     // person name/group title/topic title     var name:String      var headerBkgColor:UIColor     //30x30, person/group/topic header image     var headerImage:UIImage     //41x41, for conversation/personal info/... use, larger size image     var headerImageLarge:UIImage      //used for SelectPersonViewController     var selected:Bool     //used for indicated whether some info is updated     var isUpdated:Bool      override var description: String {         return "/(super.description),type=/(type),id=/(id),name=/(name),headerBkgColor=/(headerBkgColor),headerImage=/(headerImage),headerImageLarge=/(headerImageLarge),selected=/(selected),isUpdated=/(isUpdated)"     }  class PersonItem: ContactItem{     var personType:PersonType     var phoneNumber:String     var email:String     var position:String      override var description: String {         return "/(super.description),personType=/(personType),phoneNumber=/(phoneNumber),email=/(email),position=/(position)"     }

之后，代码：

gLog.debug("personItem=/(personItem)")

即可输出完整的信息了：

2016-05-20 21:46:39.280 [Debug] [NSOperationQueue 0x7b8c0ff0 :: NSOperation 0x7b8e5820 (QOS: LEGACY)] [ContactUtility.swift:613] parseCommonPersonJson(_:personItem:) > personItem=<JianDao.UserItem: 0x7b8b06c0>,type=Person,id=user-08da3990-9708-4338-ba5e-cff0586e0af8,name=crifan,headerBkgColor=UIDeviceRGBColorSpace 0.964706 0.701961 0.498039 1,headerImage=<UIImage: 0x7b646f60>, {30, 30},headerImageLarge=<UIImage: 0x7b646e20>, {41, 41},selected=false,isUpdated=false,personType=Myself,phoneNumber=13800000000,email=crifan@daryun.com,position=iOS技

【总结】

给对象加上继承符合CustomStringConvertible 协议，然后实现对应的var description: String即可

比如：

class ContactItem:NSObject, NSCoding, CustomStringConvertible {     var id:String     // person name/group title/topic title     var name:String      override var description: String {         return "/(super.description),id=/(id),name=/(name)"     } }

即可。

这样以后再去用print（或者别的log函数）去打印该变量，就不会再输出：

xxx Object

而是输出对应的description的string值了。

原文 http://www.crifan.com/swift_add_print_object_class_decription_string_info/

正文到此结束