我想在init
中编写swift
方法,我在NSObject
Objective-C
模型类
-(id)initWithNewsDictionary:(NSDictionary *)dictionary
{
self = [super init];
if (self) {
self.title = dictionary[@"title"];
self.shortDescription = dictionary[@"description"];
self.newsDescription = dictionary[@"content:encoded"];
self.link = dictionary[@"link"];
self.pubDate = [self getDate:dictionary[@"pubDate"]];
}
return self;
}
如何在swift
中编写此方法?
答案 0 :(得分:60)
这可能是你班级的良好基础,我想:
class MyClass {
// you may need to set the proper types in accordance with your dictionarty's content
var title: String?
var shortDescription: String?
var newsDescription: String?
var link: NSURL?
var pubDate: NSDate?
//
init () {
// uncomment this line if your class has been inherited from any other class
//super.init()
}
//
convenience init(_ dictionary: Dictionary<String, AnyObject>) {
self.init()
title = dictionary["title"] as? NSString
shortDescription = dictionary["shortDescription"] as? NSString
newsDescription = dictionary["newsDescription"] as? NSString
link = dictionary["link"] as? NSURL
pubDate = self.getDate(dictionary["pubDate"])
}
//
func getDate(object: AnyObject?) -> NSDate? {
// parse the object as a date here and replace the next line for your wish...
return object as? NSDate
}
}
我想避免将密钥复制粘贴到项目中,因此我会将可能的密钥放入例如这样enum
:
enum MyKeys : Int {
case KeyTitle, KeyShortDescription, KeyNewsDescription, KeyLink, KeyPubDate
func toKey() -> String! {
switch self {
case .KeyLink:
return "title"
case .KeyNewsDescription:
return "newsDescription"
case .KeyPubDate:
return "pubDate"
case .KeyShortDescription:
return "shortDescription"
case .KeyTitle:
return "title"
default:
return ""
}
}
}
您可以改进convenience init(...)
方法,例如这个,以及将来你可以避免代码中任何可能的错误输入错误:
convenience init(_ dictionary: Dictionary<String, AnyObject>) {
self.init()
title = dictionary[MyKeys.KeyTitle.toKey()] as? NSString
shortDescription = dictionary[MyKeys.KeyShortDescription.toKey()] as? NSString
newsDescription = dictionary[MyKeys.KeyNewsDescription.toKey()] as? NSString
link = dictionary[MyKeys.KeyLink.toKey()] as? NSURL
pubDate = self.getDate(dictionary[MyKeys.KeyPubDate.toKey()])
}
注意:这只是你如何做到这一点的原始想法,根本没有必要使用常规初始化器,但它看起来很明显,因为我对你的最后一堂课一无所知 - 你只分享了一种方法。
答案 1 :(得分:9)
class myClass {
var text: String
var response: String?
init(text: String) {
self.text = text
}
}
请参阅Swift: Initialization(下次最好自己谷歌...)
答案 2 :(得分:6)
不需要从其他类调用此方法,它将自动调用
override init()
{
super.init()
//synthesize.delegate = self
// println("my array elements are \(readingData)")
}
答案 3 :(得分:1)