ios - 如何使用委托(delegate)将数据从页脚单元格传递到 View Controller ？

Question

我一直试图将数据从 FoodEatenController(FEC) Footer 传递到 TotalCaloriesController。我现在拥有的代码在 TotalCalorieController(TCC) 的 calorieLbl 中没有显示任何内容。

我一直用来将数据从 FEC 传递到 TCC 的委托(delegate)不会将 FoodFooter calorieTotallbl 中的文本/字符串数据传递到 TEC calorieLbl

填充 FEC 单元格的数据从 Cloud Firestore 检索并从另一个 View Controller (FoodPickerController) 传入

import UIKit

class FoodEatenController: UIViewController{

    var selectedFood: FoodList!       // allows data to be passed into the VC

    // allows data to be sepearted into sections
    var foodItems: [FoodItem] = []
    var groupedFoodItems: [String: [FoodItem]] = [:]
    var dateSectionTitle: [String] = []

    @IBOutlet weak var tableView: UITableView!

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let vc = segue.destination as? TotalCalorieController {

        }
    }
}

extension FoodEatenController: UITableViewDelegate, UITableViewDataSource{

    func numberOfSections(in tableView: UITableView) -> Int {
        return dateSectionTitle.count
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        let date = dateSectionTitle[section]
        return groupedFoodItems[date]!.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let foodCell = tableView.dequeueReusableCell(withIdentifier: "FoodCell") as! FoodCell

        let date = dateSectionTitle[indexPath.section]
        let foodItemsToDisplay = groupedFoodItems[date]![indexPath.row]
        foodCell.configure(withCartItems: fooditemsToDisplay.foodList)

        return foodCell
    }

    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        let foodHeader = tableView.dequeueReusableCell(withIdentifier: "FoodHeader") as! FoodHeader

        let headerTitle = dateSectionTitle[section]
        foodHeader.dateLbl.text = "Date: \(headerTitle)"

        return foodHeader
    }

    func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {
        let foodFooter = tableView.dequeueReusableCell(withIdentifier: "FoodFooter") as! FoodFooter

        let date = dateSectionTitle[section]
        let arrAllItems = groupedFoodItems[date]!

        var total: Float = 0
        for item in arrAllItems {
            let eaten = item.productList
            let selectedMeal = item.foodList.selectedOption
            if selectedMeal == 1 {
                total = total + (Float(eaten!.calorie))
            }
        }
        foodFooter.calorieTotal.text = String(subtotal!)
        foodFooter.delegate = self

        return foodFooter
        }

}

extension FoodEatenController: EatenFoodDelegate {
    func onTouchCaloireInfo(info: String) {
        let popUp = self.storyboard?.instantiateViewController(withIdentifier: "AdditionalCostsVC") as! TotalCalorieController
        popUp.calorieLbl.text = info
    }

}

---

import UIKit

protocol EatenFoodDelegate: class {
    func onTouchCaloireInfo(info: String)
}

class FoodFooter: UITableViewCell {

    weak var delegate: EatenFoodDelegate? = nil

    @IBOutlet weak var calorieTotal: UILabel!
    @IBOutlet weak var totalInfoBtn: UIButton!     

    @IBAction func totalOnClicked(_ sender: AnyObject) {
        self.delegate?. onTouchCaloireInfo(info: calorieTotal.text!)
    }
}

---

class TotalCalorieController: UIViewController, EatenFoodDelegate {

    func onTouchCaloireInfo(info: String) {
        calorieLbl.text = info
    }

    @IBOutlet weak var calorieLbl: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()


    }
    @IBAction func returnButton(_ sender: Any) {
        dismiss(animated: true, completion: nil)
        print("Close Taxes and Fees")
    }    
}

Answer 1

在 func onTouchCaloireInfo(info:) 的末尾添加以下行

self.present(popUp, animated: true, completion: nil)

如果您想确保函数 onTouchCaloireInfo(info:) 被调用，只需添加以下行:

debugPrint("onTouchCaloireInfo")

然后检查它是否在 Xcode 的控制台中打印给定的字符串

---

extension FoodEatenController: EatenFoodDelegate {
    func onTouchCaloireInfo(info: String) {
        debugPrint("onTouchCaloireInfo")
        let popUp = self.storyboard?.instantiateViewController(withIdentifier: "AdditionalCostsVC") as! TotalCalorieController

        self.present(popUp, animated: true) {
            popUp.calorieLbl.text = info
        }
    }
}