如何从另一个类导入或访问 UITextField

Question

我在主 VC 中有 UITextField 的 Outlet，我想从另一个类访问它的文本...更多说明请参见下面的代码：

class ProductManagement : UIViewController, UITextFieldDelegate{

    @IBOutlet weak var ProductName: UITextField!

}

我想阅读下面课程中的文字

import Firebase
import FirebaseStorage

class XUpload {
    
    
    static func UploadImage(Image : UIImage, Completion : @escaping (_ url : String)->()) {
        
        guard let imageData = Image.pngData()  else { return }
                let storage = Storage.storage().reference()
        let pathRef = storage.child("Images/Products")
        
        let imageRef = pathRef.child(   // I want the product name to be written here!  )
        

            imageRef.putData(imageData, metadata: nil) { (meta, error) in
            imageRef.downloadURL { (url, error) in
                print (url as Any)
                                                
            }
        }
    }
    
    
    
}

我尝试创建一个自定义协议来委派 UITextField，但问题是我无法在 XUpload 类中符合它！！

请有人帮我写一下我的代码应该是怎样的，因为我是 Swift 语言的初学者和新手。

提前谢谢你。

编辑：

Elia 答案应用如下：

ProductManagement 类 + 扩展

    class ProductManagement : UIViewController, UITextFieldDelegate{
    
    override func viewDidLoad() {
            super.viewDidLoad()
        
            self.ProductName.delegate = self
    }
    
    
        @IBOutlet weak var ProductName: UITextField!
        @objc private func textFieldDidChange(_ sender: UITextField) {
            NotificationCenter.default.post(name: .PnameInputText, object: nil, userInfo: ["text": sender.text!])
        }
    
    
    }


extension Notification.Name {
    public static var PnameInputText = Notification.Name("PnameInputText")
}

XUpload 类

import Firebase
import FirebaseStorage

class XUpload {
    
    private init() {
        NotificationCenter.default.addObserver(self, selector: #selector(handle(_:)), name: .PnameInputText, object: nil)
    }
    
    public static var shared = XUpload()
    
    var textFieldText : String = "" {
        didSet {print("updated value > ", textFieldText)}
    }
    

    @objc private func handle(_ sender: Notification) {
        if let userInfo = sender.userInfo as NSDictionary?, let text = userInfo["text"] as? String {
        textFieldText = text
        }
    }
        
    
    
    
    static func UploadImage(Image : UIImage, Completion : @escaping (_ url : String)->()) {
        
        guard let imageData = Image.pngData()  else { return }
        
        let storage = Storage.storage().reference()
        let pathRef = storage.child("Images/Products")
        let imageRef = pathRef.child("img_"+shared.textFieldText)
        print("var of textFieldText value: " + shared.textFieldText)  //print nothing... empty value!!
        
                
        imageRef.putData(imageData, metadata: nil) { (meta, error) in
            imageRef.downloadURL { (url, error) in
                print ("Image uploaded to this link >> " + url!.description)
                guard let str = url?.absoluteString else { return }
                Completion (str)
            }
        }
    }
    
}



extension UIImage {
    
    func upload(completion : @escaping (_ url : String) ->()) {
        XUpload.UploadImage(Image: self) { (ImageURL) in completion (ImageURL)
                        
        }
    }
}

如您所见，通知中心没有给 var textFieldText 赋值！为什么？？

Answer 1

class ProductManagement : UIViewController, UITextFieldDelegate{
    var productInputText: String = ""
    @IBOutlet weak var ProductName: UITextField!

    override func viewDidLoad() { 
        super.viewDidLoad() 
        ProductName.addTarget(self, action: #selector(textFieldDidChange), for: .editingChanged)
    }

    @objc private func textFieldDidChange(_ sender: UITextField) {
         productInputText = sender.text ?? ""
    }

}

这会将您的输入文本存储到一个变量中，主要是监听编辑更改。

如果我没记错的话，你可以在 ProductManagement 类中使用 UploadImage。如下向UploadImage 添加函数属性

class XUpload {
    
    
    static func UploadImage(Image : UIImage, productName: String,  Completion : @escaping (_ url : String)->()) {
        
        guard let imageData = Image.pngData()  else { return }
                let storage = Storage.storage().reference()
        let pathRef = storage.child("Images/Products")
        
        let imageRef = pathRef.child(   // I want the product name to be written here!  )
        

            imageRef.putData(imageData, metadata: nil) { (meta, error) in
            imageRef.downloadURL { (url, error) in
                print (url as Any)
                                                
            }
        }
    }
    
    
    
}

并在ProductManagement 类中调用它，如下所示。

XUpload.UploadImage(image: myImage, productName: productInputText, Completion: { 

}

编辑：

在收到您的评论后，我决定最好的方法是使用 Notification，您在 ProductManagement 类中使用 UITextField，因此无需在 XUpload 中处理它们的 delegate 方法

描述通知名称

extension Notification.Name {
    public static var TextChange = Notification.Name("TextChange")
}

在ProductManagement、textDidChange 方法中发布文本到Notification

@objc private func textFieldDidChange(_ sender: UITextField) {
        NotificationCenter.default.post(name: .TextChange, object: nil, userInfo: ["text": sender.text])
    }

我将您的 XUpload 类转换为 Singleton 类。

class XUpload {
    
    private init() {
        NotificationCenter.default.addObserver(self, selector: #selector(handle(_:)), name: .TextChange, object: nil)
    }
    
    public static var Shared = XUpload()

    @objc private func handle(_ sender: Notification) {
        if let userInfo = sender.userInfo as NSDictionary?, let text = userInfo["text"] as? String {
            textFieldText = text
        }
        
    }
    
    var textFieldText: String = "" {
        didSet {
            print("updated value > " , textFieldText)
        }
    }
    
    static func uploadImage() {
        // use updated textfield text with textFieldText
    }
    
    
}

然后在ProductManagement 类中存储一个变量作为单例对象，它会为你工作。文本字段中的文本会更新 XUpload 类中的每次更改。

class ProductManagement : UIViewController, UITextFieldDelegate{
   var staticVariable = XUpload.Shared
}