swift - 无法在 XCODE 中将类型“ForumViewController”的返回表达式转换为返回类型“UITableViewCell”错误

Question

我的代码：

//
//  ForumViewController.swift
//  Kode4Kids
//
//  Created by Caleb Clegg on 17/06/2020.
//  Copyright © 2020 Group9. All rights reserved.
//

    import UIKit

    class ForumViewController: UIViewController, UITableViewDelegate, UITableViewDataSource  {
    
    class PostTableViewCell: UITableView{
        
        @IBOutlet weak var usernameLabel: UILabel!
        @IBOutlet weak var profileImageView: UIImageView!
        @IBOutlet weak var subtitleLabel: UILabel!
        @IBOutlet weak var postTextLabel: UILabel!
        
        override func awakeFromNib() {
            super.awakeFromNib()
            //initialization stuff
        }
        
        func set(post:Post) {
            usernameLabel.text = post.author
            postTextLabel.text = post.text
        }
        
}
    
    
    var tableView: UITableView!
    
    var posts = [
        
        Post(id: "1", author: "Ryan Johnston", text: "Kode4Kids Just Launched!"),
        Post(id: "2", author: "Caleb Clegg", text: "Woah This Is Lit!!"),
        Post(id: "3", author: "Habib Yusuf", text: "I LOVE THIS APP!"),
        Post(id: "4", author: "Maggie Mogul", text: "Gonna learn some HTML"),
        Post(id: "5", author: "Anthony Smith", text: "Just finished learning Python!"),
        Post(id: "6", author: "Renee Miseer", text: "So excited to start learning!"),
        Post(id: "7", author: "Alicia Keys", text: "Gonna stop singing to pick up code!"),
        Post(id: "8", author: "Dwayne Johnson", text: "Ah great craic"),
        Post(id: "9", author: "My dad", text: "okay"),
        Post(id: "10", author: "Kaiser Chief", text: "Sweeet app!"),
        Post(id: "12", author: "Darryl Granberry", text: "RUN IT UPP"),
        Post(id: "13", author: "Future", text: "Big racks on this app!")
    ]

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        tableView = UITableView(frame: view.bounds, style: .plain)
        tableView.backgroundColor = UIColor.white
        let cellNib = UINib(nibName: "ForumViewCell", bundle: nil)
        tableView.register(cellNib, forCellReuseIdentifier: "ForumCell")
        view.addSubview(tableView)
        
        var layoutGuide:UILayoutGuide!
        
        if #available(iOS 11.0, *){
        layoutGuide = view.safeAreaLayoutGuide
        } else {
            //fallback on previous versions
            layoutGuide = view.layoutMarginsGuide
        }
        tableView.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor).isActive = true
        tableView.topAnchor.constraint(equalTo: layoutGuide.topAnchor).isActive = true
        tableView.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: layoutGuide.bottomAnchor).isActive = true
        
        tableView.delegate = self
        tableView.dataSource = self
        tableView.reloadData()
    }
    
    
    
    
    @IBAction func backTapped(_ sender: Any) {
        
        let homeViewController = self.storyboard?.instantiateViewController(identifier: Constants.Storyboard.homeViewController) as? HomeViewController
                       
                       self.view.window?.rootViewController = homeViewController
                       self.view.window?.makeKeyAndVisible()
    }
    
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return posts.count
    }
    
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "ForumCell", for: indexPath) as! ForumViewController
        return cell
        cell.set(post: posts[indexPath.row])
        
    }

}

努力解决 cellForRow 部分中出现的这个错误。不太确定我需要改变什么。我会很感激任何帮助。这张图显示了错误，直到我输入 ""ForumCell", for: indexPath) as!ForumViewController" 才显示错误。我不明白为什么会显示错误

标签： swiftxcode

Answer 1

你需要给细胞而不是控制器

     // it should be UITableViewCell instead of UITableView
    
    class PostTableViewCell: UITableViewCell {
        
        @IBOutlet weak var usernameLabel: UILabel!
        @IBOutlet weak var profileImageView: UIImageView!
        @IBOutlet weak var subtitleLabel: UILabel!
        @IBOutlet weak var postTextLabel: UILabel!
        
        override func awakeFromNib() {
            super.awakeFromNib()
            //initialization stuff
        }
        
        func set(post:Post) {
            usernameLabel.text = post.author
            postTextLabel.text = post.text
        }
        
    }


class ForumViewController: UIViewController, UITableViewDelegate, UITableViewDataSource  {   
    
    var tableView: UITableView!
    
    var posts = [
        
        Post(id: "1", author: "Ryan Johnston", text: "Kode4Kids Just Launched!"),
        Post(id: "2", author: "Caleb Clegg", text: "Woah This Is Lit!!"),
        Post(id: "3", author: "Habib Yusuf", text: "I LOVE THIS APP!"),
        Post(id: "4", author: "Maggie Mogul", text: "Gonna learn some HTML"),
        Post(id: "5", author: "Anthony Smith", text: "Just finished learning Python!"),
        Post(id: "6", author: "Renee Miseer", text: "So excited to start learning!"),
        Post(id: "7", author: "Alicia Keys", text: "Gonna stop singing to pick up code!"),
        Post(id: "8", author: "Dwayne Johnson", text: "Ah great craic"),
        Post(id: "9", author: "My dad", text: "okay"),
        Post(id: "10", author: "Kaiser Chief", text: "Sweeet app!"),
        Post(id: "12", author: "Darryl Granberry", text: "RUN IT UPP"),
        Post(id: "13", author: "Future", text: "Big racks on this app!")
    ]

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        tableView = UITableView(frame: view.bounds, style: .plain)
        tableView.backgroundColor = UIColor.white
        let cellNib = UINib(nibName: "ForumViewCell", bundle: nil)
        tableView.register(cellNib, forCellReuseIdentifier: "ForumCell")
        view.addSubview(tableView)
        
        var layoutGuide:UILayoutGuide!
        
        if #available(iOS 11.0, *){
        layoutGuide = view.safeAreaLayoutGuide
        } else {
            //fallback on previous versions
            layoutGuide = view.layoutMarginsGuide
        }
        tableView.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor).isActive = true
        tableView.topAnchor.constraint(equalTo: layoutGuide.topAnchor).isActive = true
        tableView.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: layoutGuide.bottomAnchor).isActive = true
        
        tableView.delegate = self
        tableView.dataSource = self
        tableView.reloadData()
    }
    
    
    
    
    @IBAction func backTapped(_ sender: Any) {
        
        let homeViewController = self.storyboard?.instantiateViewController(identifier: Constants.Storyboard.homeViewController) as? HomeViewController
                       
                       self.view.window?.rootViewController = homeViewController
                       self.view.window?.makeKeyAndVisible()
    }
    
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return posts.count
    }
    
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
            let cell = tableView.dequeueReusableCell(withIdentifier: "ForumCell", for: indexPath) as! PostTableViewCell
            return cell
            cell.set(post: posts[indexPath.row])
            
        }

}