swift - NSCoder 无法解码 Float

Question

我定义了一个具有 [String] 和 Float 属性的类，它在 NSCoder 的编码过程中工作正常，但在解码时总是失败。我在代码中添加了guard let，发现是Float $的问题。

我不知道Float出了什么问题，我确实看到了一些问题Fail to decode Int with NSCoder in Swift网上说它与可选属性有关，但在我的情况下它不是可选变量。

如有任何建议，我们将不胜感激。

import UIKit
class aBill : NSObject, NSCoding {
//MARK: - Properties
var payer: [String]
var getter: [String]
var $: Float

struct PropertyKey {
    static let payer = "payer"
    static let getter = "getter"
    static let money = "$"
}

// MARK: - Initialization
init?(payer: [String], getter: [String], $: Float) {
    // Initialize stored properties.
    self.payer = payer
    self.getter = getter
    self.$ = $
    self.currency = currency
    self.remark = itemName

    super.init()

}

//MARK: - NSCoding properties
func encode(with aCoder: NSCoder) {
    aCoder.encode(payer, forKey: PropertyKey.payer)
    aCoder.encode(getter, forKey: PropertyKey.getter)
    aCoder.encode($, forKey: PropertyKey.money)
}

required convenience init?(coder aDecoder: NSCoder) {

    // The name is required. If we cannot decode a name string, the initializer should fail.
    guard let payer = aDecoder.decodeObject(forKey: PropertyKey.payer) as? [String]
        else {
            print("Unable to decode the payer name for a aBill object.")
            return nil
    }

    guard let getter = aDecoder.decodeObject(forKey: PropertyKey.getter) as? [String]
        else {
            print("Unable to decode the getter name for a aBill object.")
            return nil
    }
    guard let money = aDecoder.decodeObject(forKey: PropertyKey.money) as? Float
        else {
            print("Unable to decode the $ for a aBill object. ")
            return nil
    }

    print("Start convenience init")
    self.init(payer: payer, getter: getter, $: money)
    print("Sucess convenience init")
}

//MARK: Archiving Paths
static let DocumentsDirectory = FileManager().urls(for: .documentDirectory, in: .userDomainMask).first!
static let ArchiveURL = DocumentsDirectory.appendingPathComponent("aBill")}

}

Answer 1

你可以尝试一下aCoder.encode(<#T##realv: Float##Float#>, forKey: <#T##String#>)和aDecoder.decodeFloat(forKey: <#T##String#>)因为ecodeforkey是针对对象的。