如何在 Swift 中为 NSObject 模型变量添加值？

Posted 2023-02-23

【中文标题】如何在 Swift 中为 NSObject 模型变量添加值？

【英文标题】：How to add Values to NSObject Model Variables in Swift?

【发布时间】：2020-05-23 11:12:24

【问题描述】：

我创建了单独的 NSObject 类，名为 ProfileModel

如下：

class ProfileModel  : NSObject, NSCoding

var userId : String!
var phone : String!
var firstName : String!
var email : String!
var profileImageUrl : String!
var userAddresses : [ProfileModelUserAddress]!

// Instantiate the instance using the passed dictionary values to set the properties values
init(fromDictionary dictionary: [String:Any])
    userId = dictionary["userId"] as? String
    phone = dictionary["phone"] as? String
    firstName = dictionary["firstName"] as? String
    email = dictionary["email"] as? String
    profileImageUrl = dictionary["profileImageUrl"] as? String

/**
 * Returns all the available property values in the form of [String:Any] object where the key is the approperiate json key and the value is the value of the corresponding property
 */
func toDictionary() -> [String:Any]

    var dictionary = [String:Any]()
    if userId != nil
        dictionary["userId"] = userId
    
    if phone != nil
        dictionary["phone"] = phone
    
    if firstName != nil
        dictionary["firstName"] = firstName
    
    if email != nil
        dictionary["email"] = email
    
    if profileImageUrl != nil
        dictionary["profileImageUrl"] = profileImageUrl
    
    return dictionary


/**
 * NSCoding required initializer.
 * Fills the data from the passed decoder
 */
@objc required init(coder aDecoder: NSCoder)

    userId = aDecoder.decodeObject(forKey: "userId") as? String
    userType = aDecoder.decodeObject(forKey: "userType") as? String
    phone = aDecoder.decodeObject(forKey: "phone") as? String
    firstName = aDecoder.decodeObject(forKey: "firstName") as? String
    email = aDecoder.decodeObject(forKey: "email") as? String
    profileImageUrl = aDecoder.decodeObject(forKey: "profileImageUrl") as? String

/**
 * NSCoding required method.
 * Encodes mode properties into the decoder
 */
@objc func encode(with aCoder: NSCoder)

    if userId != nil
        aCoder.encode(userId, forKey: "userId")
    
    if phone != nil
        aCoder.encode(phone, forKey: "phone")
    
    if firstName != nil
        aCoder.encode(firstName, forKey: "firstName")
    
    if email != nil
        aCoder.encode(email, forKey: "email")
    
    if profileImageUrl != nil
        aCoder.encode(profileImageUrl, forKey: "profileImageUrl")
    

在 RegistrationViewController 中，我添加了我需要在 ProfileViewController 中显示的 firstName 值如何？

在 RegistrationViewController 中，我在 ProfileViewController 中添加了我需要的 firstName and phone 值：

class RegistrationViewController: UIViewController, UITextFieldDelegate 

@IBOutlet weak var firstNameTextField: FloatingTextField!
var userModel : ProfileModel?

override func viewDidLoad() 
     let userID: String=jsonObj?["userId"] as? String ?? ""
     self.userModel?.firstName = self.firstNameTextField.text
      self.userModel?.phone = phoneTextField.text

这是name and number 中的 ProfileViewController 我没有得到名字和电话值，为什么？：

class ProfileViewController: UIViewController 
@IBOutlet var name: UILabel!
@IBOutlet var number: UILabel!
var userModel : ProfileModel? 

override func viewDidLoad() 
    super.viewDidLoad()
    // Do any additional setup after loading the view.
    name.text = userModel?.firstName
    number.text = userModel?.phone

请帮我写代码。

【问题讨论】：

如何在两个视图控制器之间传递模型实例？

@Paulw11，我应该像这样通过`var userModel = ProfileModel()`

@Paulw11，如何将 firstNameTextField.text 值添加到 userModel?.firstName 请帮忙

您是否真的在任何地方创建了ProfileModel 的实例？您需要创建一个实例，然后将该实例传递给第二个视图控制器。

@Paulw11 你能告诉我如何创建实例和传递数据

【参考方案1】：

您不能将 firstName 或 phone 设置为 nil 的 userModal。首先你应该创建一个实例，然后你可以通过你的控制器传递它。我们应该逐步更改代码：

class ProfileModel 
    var userId : String?
    var phone : String?
    var firstName : String?
    var email : String?
    var profileImageUrl : String?
    var userAddresses : [ProfileModelUserAddress]?

    init() 

其次，您需要从两个 ViewController 类中访问 ProfileModel 实例。为此，您可以创建一个单例类：

class ProfileManager 
    static var shared = ProfileManager()

    var userModel: ProfileModel?

    private init() 

然后你可以从你的两个 ViewController 访问它：

class RegistrationViewController: UIViewController, UITextFieldDelegate 

    @IBOutlet weak var firstNameTextField: FloatingTextField!

    override func viewDidLoad() 
        super.viewDidLoad()
        let userModel = ProfileModel()
        userModel.firstName = self.firstNameTextField.text
        ProfileManager.shared.userModel = userModel
    

其他风投：

class ProfileViewController: UIViewController 
    @IBOutlet var name: UILabel!

    override func viewDidLoad() 
        super.viewDidLoad()
        if let userModel = ProfileManager.shared.userModel,
            let firstName = userModel.firstName 
            name.text = firstName
        
    

根据需要修改它。