Question

我的代表在协议中的使用存在问题，很多人面临同样的问题，但没有答案适合我。

我的第一堂课是FavorisHeaderTableView

import UIKit

protocol FavorisHeaderDelegate {
func changeFavoris(sender: FavorisHeaderTableViewCell)
}

class FavorisHeaderTableViewCell: UITableViewCell {

@IBOutlet weak var lblTitle: UILabel!
@IBOutlet weak var txtFavoriteNameInput: UITextField!
@IBOutlet weak var lblIcon: UILabel!
@IBOutlet weak var lblTime: UILabel!
@IBOutlet weak var lblDescription: UILabel!

@IBOutlet weak var btnFavHeart: UIButton!
@IBOutlet weak var btnFavHome: UIButton!
@IBOutlet weak var btnFavShop: UIButton!
@IBOutlet weak var btnFavWork: UIButton!
@IBOutlet weak var btnFavGolf: UIButton!


var myDelegate: FavorisHeaderDelegate? = nil


var defaultIcon:FavIconType = .heart

var selectedIcon:UIButton? = nil {
    didSet {
        selectedIcon!.backgroundColor = Design.Palette.red
        selectedIcon?.layer.cornerRadius = 3
        selectedIcon?.tintColor = Design.Palette.white
    }
    willSet {
        if selectedIcon != nil {
            selectedIcon!.backgroundColor = UIColor.clear
            selectedIcon?.tintColor = UIColor(red:0.671, green:0.651, blue:0.635, alpha:1)
        }
    }
}

@IBAction func didSelectIcon(_ sender: UIButton) {

    selectedIcon = sender
    self.myDelegate?.changeFavoris(sender: self)

}

@IBAction func changeTitle(_ sender: Any) {

    txtFavoriteNameInput.text = "gare centro"

    print("delegate: ",myDelegate)
    if myDelegate != nil {
        myDelegate?.changeFavoris(sender: self)
    }
}


override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
}

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
}
}

使用该协议的第二类是

addFavoriteViewController: UIViewController {

// MARK properties
let defaultLocalizer = AMPLocalizeUtils.defaultLocalizer
var favorisName:String? = nil
var defaultIcon:FavIconType = .heart

var delegate:handleFavorite? = nil

@IBOutlet weak var favTableView: UITableView!

var headerCell:FavorisHeaderTableViewCell?

override func viewDidLoad() {
    super.viewDidLoad()


    // Localization of labels
    //lblAddToFavorite.text = defaultLocalizer.stringForKey(key: "str_favorites_addTitle")
    //lblFavoriteName.text = defaultLocalizer.stringForKey(key: "str_favorites_nameInput")

    favTableView.delegate = self
    favTableView.dataSource = self


    self.headerCell?.myDelegate = self
}

override func viewWillAppear(_ animated: Bool) {
    // Text Field
    //favorisName.clearButtonMode = .whileEditing

}

var place:PlaceModel? = nil
var itinerary:(source:PlaceModel, destination:PlaceModel)? = nil
let db = DataController.shared
var favorite:FavoritesMO? = nil

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
}

extension UGOaddFavoriteViewController: FavorisHeaderDelegate {
func changeFavoris(sender: FavorisHeaderTableViewCell) {

    defaultIcon = sender.defaultIcon
    favorisName = sender.txtFavoriteNameInput.text
}
}

当我尝试这段代码时，“myDelegate”总是为零而且我不明白什么是错的，尽管所有主题都是关于这个问题的。

Answer 1

您将from tkinter import * root = Tk() def login(variable): print("Login triggered") login_button = Button(root, text="Login", command=lambda: login("variable")) login_button.pack() root.mainloop()设置为错误单元格的委托！

下面：

self

您将self.headerCell?.myDelegate = self的委托设置为headerCell，但self实际上从未显示在屏幕上！

您需要在屏幕上实际设置单元格的委托，而不是您创建的随机单元格的委托。

执行此操作的最佳位置是headerCell：

cellForRowAtIndexPath

自定义代表总是零

1 个答案: