【发布时间】：2024-01-02 18:35:01
【问题描述】：
我正在使用 Swift 开发一个应用程序，但我遇到了自定义单元格的问题。我有一个自定义单元格，当您单击添加按钮时，它会创建另一个自定义单元格。单元格有 3 个文本字段和 2 个按钮。这些文本字段是我正在创建的膳食成分的名称、价格和数量。当我只使用一个自定义单元格或再添加一个以使其成为两个时，数据将正确存储。但是当我添加 2 个自定义单元格（总共 3 个自定义单元格）时，我遇到了价格错误的问题，只计算了最后两种成分的价格。当我添加 3 个自定义单元格（总共 4 个自定义单元格）时，它只会重新创建第一个单元格，其中包含第一个单元格中的填充数据。 在完成按钮点击时，我收到一个致命错误：在展开可选值时发现 nil。
视图控制器
import UIKit
import CoreData
class AddMealViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UITextFieldDelegate {
@IBOutlet weak var mealNameTF: UITextField!
@IBOutlet weak var addMealsCell: UITableViewCell!
@IBOutlet weak var finishButton: UIButton!
@IBOutlet weak var resetButton: UIButton!
@IBOutlet weak var addButton: UIButton!
@IBOutlet weak var addMealTableView: UITableView!
@IBOutlet weak var productPrice: UILabel!
let currency = "$" // this should be determined from settings
var priceTotal = "0"
override func viewDidLoad() {
super.viewDidLoad()
addMealTableView.delegate = self
addMealTableView.dataSource = self
borderToTextfield(textField: mealNameTF)
mealNameTF.delegate = self
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
self.view.endEditing(true)
return true;
}
}
func numberOfSections(in tableView: UITableView) -> Int {
return counter
}
var counter = 1
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return counter
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier:
"addMealsCell", for: indexPath) as! AddMealsTableViewCell
borderToTextfield(textField: (cell.amountTF)!)
borderToTextfield(textField: (cell.ingredientNameTF)!)
//borderToTextfield(textField: cell.normativeTF)
borderToTextfield(textField: (cell.priceTF)!)
return cell
}
@IBAction func addButton(_ sender: UIButton) {
counter += 1
addMealTableView.register(AddMealsTableViewCell.self, forCellReuseIdentifier: "addMealsCell")
addMealTableView.reloadData()
}
@IBAction func resetButton(_ sender: UIButton) {
mealNameTF.text = ""
for c in 0..<counter{
let indexPath = IndexPath(row: c, section:0)
let cell = addMealTableView.cellForRow(at: indexPath) as! AddMealsTableViewCell
cell.amountTF.text = ""
cell.ingredientNameTF.text = ""
// cell.normativeTF.text = ""
cell.priceTF.text = ""
}
productPrice.text = "\(currency)0.00"
priceTotal = "0"
counter = 1
}
@IBAction func finishButton(_ sender: UIButton) {
for c in (0..<counter){
if let cell = addMealTableView.cellForRow(at: IndexPath(row: c, section: 0)) as? AddMealsTableViewCell {
cell.amountTF.delegate = self
cell.ingredientNameTF.delegate = self
// cell.normativeTF.delegate = self
cell.priceTF.delegate = self
guard cell.priceTF.text?.isEmpty == false && cell.amountTF.text?.isEmpty == false && mealNameTF.text?.isEmpty == false && cell.ingredientNameTF.text?.isEmpty == false
else {
return
}
if cell.priceTF.text?.isEmpty == false{
// if (true) {
let tfp = Double((cell.priceTF.text!))!*Double((cell.amountTF.text!))!
var ttp = Double(priceTotal)
ttp! += tfp
priceTotal = String(ttp!)
// }
}}
}
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
let newMeal = NSEntityDescription.insertNewObject(forEntityName: "Meal", into: context)
let mealName = mealNameTF.text
newMeal.setValue(mealName, forKey: "name")
newMeal.setValue(priceTotal, forKey: "price")
do {
try context.save()
print("Spremljeno")
} catch {
print("Neki error")
}
productPrice.text = currency + priceTotal
}
@IBAction func addNewIngredientButton(_ sender: UIButton) {
}
func borderToTextfield(textField: UITextField){
let border = CALayer()
let width = CGFloat(2.0)
border.borderColor = UIColor.white.cgColor
border.frame = CGRect(x: 0, y: textField.frame.size.height - width, width: textField.frame.size.width, height: textField.frame.size.height)
border.borderWidth = width
textField.layer.addSublayer(border)
textField.layer.masksToBounds = true
textField.tintColor = UIColor.white
textField.textColor = UIColor.white
textField.textAlignment = .center
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
self.view.endEditing(true)
return true;
}
}
单元格
class AddMealsTableViewCell: UITableViewCell, UITextFieldDelegate{
@IBOutlet weak var DropMenuButton: DropMenuButton!
@IBOutlet weak var addNewIngredient: UIButton!
@IBOutlet weak var ingredientNameTF: UITextField!
// @IBOutlet weak var normativeTF: UITextField!
@IBOutlet weak var amountTF: UITextField!
@IBOutlet weak var priceTF: UITextField!
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
self.endEditing(true)
return true;
}
override func prepareForReuse() {
self.amountTF.text = ""
self.priceTF.text = ""
self.ingredientNameTF.text = ""
}
@IBAction func DropMenuButton(_ sender: DropMenuButton) {
DropMenuButton.initMenu(["kg", "litre", "1/pcs"], actions: [({ () -> (Void) in
print("kg")
sender.titleLabel?.text = "kg"
}), ({ () -> (Void) in
print("litre")
sender.titleLabel?.text = "litre"
}), ({ () -> (Void) in
print("1/pcs")
sender.titleLabel?.text = "1/pcs"
})])
}
@IBAction func addNewIngredient(_ sender: UIButton) {
let name = ingredientNameTF.text
let amount = amountTF.text
let price = priceTF.text
// let normative = normativeTF.text
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
let newIngredient = NSEntityDescription.insertNewObject(forEntityName: "Ingredient", into: context)
newIngredient.setValue(name, forKey: "name")
// newIngredient.setValue(normative, forKey: "normative")
newIngredient.setValue(amount, forKey: "amount")
newIngredient.setValue(price, forKey: "price")
do {
try context.save()
print("Spremljeno")
} catch {
print("Neki error")
}
}
}
【问题讨论】：