Question

我正在尝试解析json并将其加载到CustomTable中，我的json解析成功但无法在UI中加载数据，我尝试添加测试数据，并显示它。所以我想这与范围有关。我曾尝试在同一个问题上使用其他答案，但仍然没有为我工作

import UIKit
import Alamofire
import SwiftyJSON

class NewsViewController: UIViewController, 
   UITableViewDelegate, UITableViewDataSource {

     @IBOutlet weak var tableView: UITableView!



    var newsPosts = [NewsPost]()

    override func viewDidLoad() {
        super.viewDidLoad()

        tableView.delegate = self
        tableView.dataSource = self

        getNewsPost()


    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let post = newsPosts[indexPath.row]

        if let cell = tableView.dequeueReusableCell(withIdentifier: "NewsCell") as? NewsPostCell{
        cell.configureCell(post: post)
        return cell
    }else{
        let cell = NewsPostCell()
        cell.configureCell(post: post)
        return cell
    }
}


func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return newsPosts.count
}


func getNewsPost(){
    Alamofire.request(URL_BASE + NEWS_URL).responseJSON { response in


        let json = JSON(data: response.data!)

        if let dict = json.dictionaryObject{
            if let result = dict["data"] as? [NSDictionary]{
                for data in result{
                    guard let title = data["title"] as? String else{
                        return print("title is nil")
                    }
                    guard let href = data["href"] as? String else{
                        return print("href is nil")
                    }
                        guard let image = data["image"] as? String else{
                            return print("image is nil")
                        }
                        guard let content = data["content"] as? String else{
                            return print("content is nil")
                        }
                        guard let _ = data["timestamp"] as? String else{
                            return print("timestamp is nil")
                        }
                        guard let type = data["type"] as? String else{
                            return print("type is nil")
                        }

                        print(type)

                        let post = NewsPost(title: title, href: href, 
                        image: image, timestamp: 
                        "1 day ago", content: content, type: type)

                        self.newsPosts.append(post)
                    }
                    self.tableView.reloadData()
                }
            }
        }
    }


}

Answer 1

我想问题是你在调用gettingNewPost函数时。在didLoad之后立即调用reloadData（）函数，当你调用函数来填充表时，你可能甚至都没有得到数据。您是否尝试登录cellForRow函数以查看是否尝试访问nil数组？

Answer 2

在重新加载数据之前，您应该测试您的tableview是否已初始化：

import UIKit
import Alamofire
import SwiftyJSON

class NewsViewController: UIViewController, 
   UITableViewDelegate, UITableViewDataSource {

     @IBOutlet weak var tableView: UITableView!



    var newsPosts = [NewsPost]()

    override func viewDidLoad() {
        super.viewDidLoad()

        tableView.delegate = self
        tableView.dataSource = self

        getNewsPost()


    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let post = newsPosts[indexPath.row]

        if let cell = tableView.dequeueReusableCell(withIdentifier: "NewsCell") as? NewsPostCell{
        cell.configureCell(post: post)
        return cell
    }else{
        let cell = NewsPostCell()
        cell.configureCell(post: post)
        return cell
    }
}


func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return newsPosts.count
}


func getNewsPost(){
    Alamofire.request(URL_BASE + NEWS_URL).responseJSON { response in


        let json = JSON(data: response.data!)

        if let dict = json.dictionaryObject{
            if let result = dict["data"] as? [NSDictionary]{
                for data in result{
                    guard let title = data["title"] as? String else{
                        return print("title is nil")
                    }
                    guard let href = data["href"] as? String else{
                        return print("href is nil")
                    }
                        guard let image = data["image"] as? String else{
                            return print("image is nil")
                        }
                        guard let content = data["content"] as? String else{
                            return print("content is nil")
                        }
                        guard let _ = data["timestamp"] as? String else{
                            return print("timestamp is nil")
                        }
                        guard let type = data["type"] as? String else{
                            return print("type is nil")
                        }

                        print(type)

                        let post = NewsPost(title: title, href: href, 
                        image: image, timestamp: 
                        "1 day ago", content: content, type: type)

                        self.newsPosts.append(post)
                    }
                    if self.tableView != nil {
                        self.tableView.reloadData()
                    }
                }
            }
        }
    }


}

Answer 3

我终于找到了这个问题，其中一个守卫是返回零，所以它停止执行其他人，所以我从使用后卫改为下面

let title = data["title"] as? String ?? ""
let href = data["href"] as? String ?? ""
let image = data["image"] as? String ?? ""
let content = data["content"] as? String ?? ""
let type = data["type"] as? String ?? ""

UITableView没有使用SwiftyJSON和Alamofire加载数据

3 个答案: