我在主VC中有UITextField的Outlet，我想从另一个类访问它的文本。。。有关更多澄清，请参阅下面的代码：
class ProductManagement : UIViewController, UITextFieldDelegate{
@IBOutlet weak var ProductName: UITextField!
}
我想阅读下面课堂中的文字
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)
}
}
}
}
我试图创建一个自定义协议来委托UITextField，但问题是我无法在XUpload类中遵守它！！
请有人为我写下我的代码应该如何，因为我是Swift语言的初学者和新手。
提前谢谢。
编辑：
Elia回答如下：
产品管理类+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)
}
}
}
正如您所看到的，通知中心没有为var textFieldText提供任何值！为什么？
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 ?? ""
}
}
这将把您的输入文本存储到一个变量中，基本上带有侦听编辑更改。
如果我没有错的话，您可以在ProductManagement类中使用UploadImage。将函数属性添加到UploadImage，如下所示
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CCD_ 4类中调用它，如下所示。
XUpload.UploadImage(image: myImage, productName: productInputText, Completion: {
}
编辑：
在得到你的评论后，我决定最好的方法是使用Notification，你在ProductManagement类中使用UITextField，所以不需要在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中，textDidChange方法将文本发布到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
}
}
然后将一个变量作为单例对象存储在ProductManagement类中，它将为您工作。textfield中的文本会更新XUpload类中的每一次更改。
class ProductManagement : UIViewController, UITextFieldDelegate{
var staticVariable = XUpload.Shared
}