Tableviewcell 数据不会转换到另一个视图控制器

Posted 2023-02-15

【中文标题】Tableviewcell 数据不会转换到另一个视图控制器

【英文标题】：Tableviewcell data won't translate to another view controller

【发布时间】：2022-01-07 16:30:09

【问题描述】：

我在我的listingshopvc中做了一个解析json，它显示了。现在我想选择一行，它会弹出另一个视图控制器，但有错误只是一个没有错误的空白页。我只想按一行并将其转换为显示在另一个视图控制器上。

我在以下视图控制器中有列表：ListingShopVc,ProductDetail,TableCellData

ListingShopVC

import UIKit
import CoreData

class ListingShopVC: UIViewController,   UITableViewDelegate, UITableViewDataSource
@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var creditsdisplay: UILabel!

var context = (UIApplication.shared.delegate as!  AppDelegate).persistentContainer.viewContext
var myUser:[User] = []
var mySecond:[Product] = []

var id:String = ""
var name:String = ""
var price:Double = 0.0
var image:String = ""
var details:String = ""

override func viewDidLoad() 
    super.viewDidLoad()
    
    fetch()
    tableView.delegate = self
    tableView.dataSource = self
    extracted()
    creditsdisplay.text = "You have 200 credits"
    
    

// MARK: - Table view data source

func numberOfSections(in tableView: UITableView) -> Int 
    // #warning Incomplete implementation, return the number of sections
    return 1


func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int 
    // #warning Incomplete implementation, return the number of rows
    return mySecond.count
    



func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell 
    let cell = tableView.dequeueReusableCell(withIdentifier: "hello", for: indexPath) as! TableCellData

    // Configure the cell...

    cell.shopTitle.text = mySecond[indexPath.row].name
    cell.shopPrice.text = "$" + String(mySecond[indexPath.row].price) + "0"
    cell.shopDesc.text = mySecond[indexPath.row].description
    
    if let url = URL(string: mySecond[indexPath.row].image)
        DispatchQueue.global().async 
            let data = try? Data(contentsOf: url)
            if let data = data 
                let image = UIImage(data: data)
            DispatchQueue.main.async 
                    cell.shopImageView.image = image
                
            
        
        
    

    
    return cell


func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) 
    
    id  = mySecond[indexPath.row].id
    name = mySecond[indexPath.row].name
    price = mySecond[indexPath.row].price
    details = mySecond[indexPath.row].description
    image = mySecond[indexPath.row].image
    
    performSegue(withIdentifier: "toDetails", sender: self)
    

override func prepare(for segue: UIStoryboardSegue, sender: Any?) 
    if segue.identifier == "toDetails"
        let vc = segue.destination as! ProductDetail
        
        vc.productPicture = image
        vc.productName = name
        vc.productPrice = price
        vc.productDetails = details
        vc.productID = id
        print(vc.productName)
    



func extracted()
    guard let url = URL(string: "http://rajeshrmohan.com/sport.json")
    else return
    
    let task = URLSession.shared.dataTask(with: url)
        (data,response,error) in
        guard let dataResponse = data,
              error == nil else 
            print(error?.localizedDescription ?? "Response Error")
            return
        
        
        do 
            let decoder = JSONDecoder()
            let model:[Product] = try decoder.decode([Product].self, from: dataResponse)
            //print(model)
            
            for i in 0..<model.count
                self.mySecond.append(model[i])
            
            DispatchQueue.main.async 
                self.tableView.reloadData()
            
        
        catch let parsingError 
            print("Error", parsingError)
        
    
    task.resume()


func fetch()
    userList = try! context.fetch(User.fetchRequest())
    
    tableView.reloadData()

TableViewCell

import UIKit

class TableCellData: UITableViewCell 


@IBOutlet weak var shopImageView: UIImageView!
@IBOutlet weak var shopTitle: UILabel!
@IBOutlet weak var shopPrice: UILabel!
@IBOutlet weak var shopDesc: UILabel!
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

产品详情

import UIKit
import CoreData

class ProductDetail: UIViewController 

var context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext

var myArray:[Cart] = []
var mySecondArray:[Products] = []

var newTots:Double = 0.0


@IBOutlet weak var AddImage: UIImageView!
@IBOutlet weak var AddTitle: UILabel!
@IBOutlet weak var AddPrice: UILabel!
@IBOutlet weak var AddDesc: UILabel!

var productID = String()
var productName = String()
var productPrice:Double = 0.0
var productPicture = String()
var productDetails:String = ""

override func viewDidLoad() 
    super.viewDidLoad()

        AddTitle.text = productName
        AddDesc.text = productDetails
        AddPrice.text = String(productPrice)
        if let imageUrl = URL(string: productPicture),
        let imageData = try? Data(contentsOf: imageUrl) 
        AddImage.image = UIImage(data: imageData)
        
    



@IBAction func add2Cart(_ sender: Any) 
    
    let neww = Cart(context: context)
    neww.image = productPicture
    neww.name = productName
    neww.desc = productDetails
    neww.price = productPrice
    neww.total = productPrice
    
    try! context.save()
    performSegue(withIdentifier: "gotoCheckout", sender: nil)


func fetch()
    self.mySecondArray = try! context.fetch(Products.fetchRequest())
 

它显示了什么 [1]：https://i.stack.imgur.com/XWUt0.png

【问题讨论】：

你有没有调试过ProductDetail的viewDidLoad，并在调用viewDidLoad的时候检查产品信息是否可用？我最好的猜测是它不是..尝试将代码放在 viewWillAppear..

尝试将下面的代码移动到 viewWillApppear 而不是 viewDidAppear AddTitle.text = productName AddDesc.text = productDetails AddPrice.text = String(productPrice) if let imageUrl = URL(string: productPicture), let imageData = try? Data(contentsOf: imageUrl) AddImage.image = UIImage(data: imageData)

同样的问题。我已经尝试了 viewwillappear 和 viewdidappear 以防万一和相同的输出。只是一个没有错误的空白页

【参考方案1】：

-> 你只需要调用表格视图didSelectRowAt的委托方法

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) 
        let tag = projectEquipmentList?[indexPath.row].tag // Object data to take in next VC
        let QR = R.storyboard.main.qrScannerVC()! // View Controller
        QR.manageVC(projectEquipmentTag: tag!) // setter method of View controller to set data
        navigationController?.pushViewController(QR, animated: true) // push to next view controller