如何使用 NSUserDefaults 将自定义数组 类 存储在 Swift 中?
How to use NSUserDefaults to store an array of custom classes in Swift?
我有一个名为 Person
的自定义 class,它会在某人输入信息时存储有关他们的各种属性。
class Person {
// Person dictionary variable
var name: String?
var age: String?
var html_url: String?
init(json: NSDictionary) { // Dictionary object
self.name = json["name"] as? String
self.age = json["age"] as? String
self.html_url = json["html_url"] as? String // Location of the JSON file
}
}
创建字典后,会将其放入数组中。点击按钮时,我无法将数组保存到 NSUserDefaults
。
personArray.append(newPerson) // newPerson = dictionary of attributes
NSUserDefaults.standardUserDefaults().setObject(personArray, forKey: "personArray")
NSUserDefaults.standardUserDefaults().synchronize()
我看过 How to store custom objects in NSUserDefaults and Saving custom SWIFT class with NSCoding to UserDefaults,但我没有运气,而且我发现它很难理解。
当我只是尝试保存到 NSUserDefaults 时,我被告知如下:
Attempt to set a non-property-list object (
"PersonApp.Person"
) as an NSUserDefaults/CFPreferences value for key personArray
谁能帮我通过 NSUserDefaults 实际保存一组自定义对象(自定义词典)?
您需要实施 NSCoding
协议才能将自定义对象存储到 NSUserDefaults
。看看这个例子 http://nshipster.com/nscoding/
你的人 class 应该是这样的:
Swift 3:
class Person : NSObject, NSCoding{
// Person dictionary variable
var name: String?
var age: String?
var html_url: String?
init(json: NSDictionary) { // Dictionary object
self.name = json["name"] as? String
self.age = json["age"] as? String
self.html_url = json["html_url"] as? String // Location of the JSON file
}
required init?(coder aDecoder: NSCoder) {
self.name = aDecoder.decodeObjectForKey("name") as? String;
self.age = aDecoder.decodeObjectForKey("age") as? String;
self.html_url = aDecoder.decodeObjectForKey("html") as? String;
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(self.name, forKey: "name");
aCoder.encodeObject(self.age, forKey: "age");
aCoder.encodeObject(self.html_url, forKey: "html");
}
}
这里有一个从 NSUserDefaults 保存和检索数组的示例:
let p = Person()
p.name = "person1"
p.age = "12"
p.html_url = "www.google.ro"
let p2 = Person()
p2.name = "person2"
p2.age = "11"
p2.html_url = "www.google.ro"
let array = [p, p2]
let userDefaults = NSUserDefaults.standardUserDefaults()
userDefaults.setValue(NSKeyedArchiver.archivedDataWithRootObject(array), forKey: "persons")
userDefaults.synchronize()
let array : [Person]
array = NSKeyedUnarchiver.unarchiveObjectWithData(userDefaults.objectForKey("persons") as! NSData) as! [Person]
print("\(array[0].name)\(array[1].name)")
Swift 4:
class Person : NSObject, NSCoding{
// Person dictionary variable
var name: String?
var age: String?
var html_url: String?
init(json: NSDictionary) { // Dictionary object
self.name = json["name"] as? String
self.age = json["age"] as? String
self.html_url = json["html_url"] as? String // Location of the JSON file
}
required init?(coder aDecoder: NSCoder) {
self.name = aDecoder.decodeObject(forKey: "name") as? String;
self.age = aDecoder.decodeObject(forKey: "age") as? String;
self.html_url = aDecoder.decodeObject(forKey: "html") as? String;
}
func encode(with aCoder: NSCoder) {
aCoder.encode(self.name, forKey: "name");
aCoder.encode(self.age, forKey: "age");
aCoder.encode(self.html_url, forKey: "html");
}
}
Swift 4
- 确认您的 class
的可编码协议
- 使用 JsonEncoder 序列化(数据)您的对象 class
- 现在将您的数据保存到 userDefaults
查看此答案以获得清晰的思路
我有一个名为 Person
的自定义 class,它会在某人输入信息时存储有关他们的各种属性。
class Person {
// Person dictionary variable
var name: String?
var age: String?
var html_url: String?
init(json: NSDictionary) { // Dictionary object
self.name = json["name"] as? String
self.age = json["age"] as? String
self.html_url = json["html_url"] as? String // Location of the JSON file
}
}
创建字典后,会将其放入数组中。点击按钮时,我无法将数组保存到 NSUserDefaults
。
personArray.append(newPerson) // newPerson = dictionary of attributes
NSUserDefaults.standardUserDefaults().setObject(personArray, forKey: "personArray")
NSUserDefaults.standardUserDefaults().synchronize()
我看过 How to store custom objects in NSUserDefaults and Saving custom SWIFT class with NSCoding to UserDefaults,但我没有运气,而且我发现它很难理解。
当我只是尝试保存到 NSUserDefaults 时,我被告知如下:
Attempt to set a non-property-list object (
"PersonApp.Person"
) as an NSUserDefaults/CFPreferences value for key personArray
谁能帮我通过 NSUserDefaults 实际保存一组自定义对象(自定义词典)?
您需要实施 NSCoding
协议才能将自定义对象存储到 NSUserDefaults
。看看这个例子 http://nshipster.com/nscoding/
你的人 class 应该是这样的:
Swift 3:
class Person : NSObject, NSCoding{
// Person dictionary variable
var name: String?
var age: String?
var html_url: String?
init(json: NSDictionary) { // Dictionary object
self.name = json["name"] as? String
self.age = json["age"] as? String
self.html_url = json["html_url"] as? String // Location of the JSON file
}
required init?(coder aDecoder: NSCoder) {
self.name = aDecoder.decodeObjectForKey("name") as? String;
self.age = aDecoder.decodeObjectForKey("age") as? String;
self.html_url = aDecoder.decodeObjectForKey("html") as? String;
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(self.name, forKey: "name");
aCoder.encodeObject(self.age, forKey: "age");
aCoder.encodeObject(self.html_url, forKey: "html");
}
}
这里有一个从 NSUserDefaults 保存和检索数组的示例:
let p = Person()
p.name = "person1"
p.age = "12"
p.html_url = "www.google.ro"
let p2 = Person()
p2.name = "person2"
p2.age = "11"
p2.html_url = "www.google.ro"
let array = [p, p2]
let userDefaults = NSUserDefaults.standardUserDefaults()
userDefaults.setValue(NSKeyedArchiver.archivedDataWithRootObject(array), forKey: "persons")
userDefaults.synchronize()
let array : [Person]
array = NSKeyedUnarchiver.unarchiveObjectWithData(userDefaults.objectForKey("persons") as! NSData) as! [Person]
print("\(array[0].name)\(array[1].name)")
Swift 4:
class Person : NSObject, NSCoding{
// Person dictionary variable
var name: String?
var age: String?
var html_url: String?
init(json: NSDictionary) { // Dictionary object
self.name = json["name"] as? String
self.age = json["age"] as? String
self.html_url = json["html_url"] as? String // Location of the JSON file
}
required init?(coder aDecoder: NSCoder) {
self.name = aDecoder.decodeObject(forKey: "name") as? String;
self.age = aDecoder.decodeObject(forKey: "age") as? String;
self.html_url = aDecoder.decodeObject(forKey: "html") as? String;
}
func encode(with aCoder: NSCoder) {
aCoder.encode(self.name, forKey: "name");
aCoder.encode(self.age, forKey: "age");
aCoder.encode(self.html_url, forKey: "html");
}
}
Swift 4
- 确认您的 class 的可编码协议
- 使用 JsonEncoder 序列化(数据)您的对象 class
- 现在将您的数据保存到 userDefaults
查看此答案以获得清晰的思路