[英]Swift: Does not conform to protocol NSCoding
我試圖在我用swift編寫的類上使用NSCoding協議,但似乎無法弄清楚為什么當我實現所需的方法時編譯器抱怨它“不符合協議NSCoding”:
class ServerInfo: NSObject, NSCoding {
var username = ""
var password = ""
var domain = ""
var location = ""
var serverFQDN = ""
var serverID = ""
override init() {
}
init(coder aDecoder: NSCoder!) {
self.username = aDecoder.decodeObjectForKey("username") as NSString
self.password = aDecoder.decodeObjectForKey("password") as NSString
self.domain = aDecoder.decodeObjectForKey("domain") as NSString
self.location = aDecoder.decodeObjectForKey("location") as NSString
self.serverFQDN = aDecoder.decodeObjectForKey("serverFQDN") as NSString
self.serverID = aDecoder.decodeObjectForKey("serverID") as NSString
}
func encodeWithCoder(_aCoder: NSCoder!) {
_aCoder.encodeObject(self.username, forKey: "username")
_aCoder.encodeObject(self.password, forKey: "password")
_aCoder.encodeObject(self.domain, forKey: "domain")
_aCoder.encodeObject(self.location, forKey: "location")
_aCoder.encodeObject(self.serverFQDN, forKey: "serverFQDN")
_aCoder.encodeObject(self.serverID, forKey: "serverID")
}
}
這是一個錯誤還是我錯過了一些東西?
正如您在報告導航器中的詳細編譯器消息中所看到的,您的方法未正確聲明:
error: type 'ServerInfo' does not conform to protocol 'NSCoding' class ServerInfo: NSObject, NSCoding { ^ Foundation.NSCoding:2:32: note: protocol requires function 'encodeWithCoder' with type '(NSCoder) -> Void' @objc(encodeWithCoder:) func encodeWithCoder(aCoder: NSCoder) ^ note: candidate has non-matching type '(NSCoder!) -> ()' func encodeWithCoder(_aCoder: NSCoder!) { ^ Foundation.NSCoding:3:25: note: protocol requires initializer 'init(coder:)' with type '(coder: NSCoder)' @objc(initWithCoder:) init(coder aDecoder: NSCoder) ^ note: candidate has non-matching type '(coder: NSCoder!)' init(coder aDecoder: NSCoder!) {
(這可能在beta版本之間發生了變化。)此外,必須將initWithCoder
方法標記為required
:
required init(coder aDecoder: NSCoder) { }
func encodeWithCoder(_aCoder: NSCoder) { }
在Swift 3中 ,所需的方法是
required init(coder aDecoder: NSCoder) { }
func encode(with aCoder: NSCoder) { }
參數不是隱式解包(刪除!),初始化程序需要required
修飾符:
required init(coder aDecoder: NSCoder) {
...
func encodeWithCoder(_aCoder: NSCoder) {
對於Swift 3
已經提出了一個小但重要的變化。 init方法相同,但encodeWithCoder方法已被修改。
required init(coder aDecoder: NSCoder) {
...
}
func encode(with _aCoder: NSCoder) {
...
}
對於Swift 3(在Xcode 8.2 beta(8C23)上)
它似乎又改變了。 這是我可以開始工作的唯一變種......
func encodeWithCoder(_ _aCoder: NSCoder) {
...
}
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