Swift 4 tableView API分页

时间:2018-11-22 21:37:54

标签: api uitableview pagination swift4

我已经成功解析并解码了JSON数据,并显示在控制台中。我不知道当我向下滚动tableView时如何设置api的分页并显示所有数据。我使用的API是https://rickandmortyapi.com/api/character/。谢谢您提前提供的所有帮助!

这是我的主ViewController中的代码

import UIKit

struct PagedCharacters: Codable {
    struct Info: Codable {
        let count: Int
        let pages: Int
        let next: String
        let prev: String
    }

    struct Results: Codable {
        let name: String
        let status: String
        let species: String
    }

    let info: Info
    let results: [Results]

}


class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet var uiTableView: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()
        getRickAndMortyData()


        self.uiTableView.dataSource = self
        self.uiTableView.delegate = self

        // Do any additional setup after loading the view.
    }

    func getRickAndMortyData() {

        //create instance of the url
        let url = "https://rickandmortyapi.com/api/character/"

        //construct the url, use guard to avoid nonoptional
        guard let urlObj = URL(string: url) else
        { return }

        //fetch data
        URLSession.shared.dataTask(with: urlObj) {(data, response, error) in

            //to avoid non optional in JSONDecoder
            guard let data = data else { return }

            do {
                //decode object
                let downloadedRickAndMorty = try JSONDecoder().decode(PagedCharacters.self, from: data)
             DispatchQueue.main.async {
                    self.uiTableView.reloadData()
                }
               print(downloadedRickAndMorty)

            } catch {
                print(error)

            }

            }.resume()

    }


    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        return 0
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        guard let cell = tableView.dequeueReusableCell(withIdentifier: "rickandmortyCell") as? CharacterTableViewCell else { return UITableViewCell() }

        cell.nameLabel.text = "Name: " + PagedCharacters.Results[indexPath.row].name

        return cell
    }


}

这是我的tableviewcell类

import UIKit

class CharacterTableViewCell: UITableViewCell {

    @IBOutlet weak var nameLabel: 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
    }

}

这是打印解析的数据时我在控制台中获取的数据。我仍然无法从不同页面获取所有数据。

  

PagedCharacters(info:API_Practice.PagedCharacters.Info(count:493,   页数:25,下一页:“ https://rickandmortyapi.com/api/character/?page=2”,   上一个:“”),结果:[API_Practice.PagedCharacters.Results(名称:“ Rick   桑切斯”,状态:“活着”,物种:“人类”),   API_Practice.PagedCharacters.Results(name:“ Morty Smith”,状态:   “ Alive”,种类:“ Human”),API_Practice.PagedCharacters.Results(名称:   “ Summer Smith”,状态:“活着”,种类:“人类”),   API_Practice.PagedCharacters.Results(name:“ Beth Smith”,状态:   “ Alive”,种类:“ Human”),API_Practice.PagedCharacters.Results(名称:   “杰里·史密斯”,状态:“还活着”,物种:“人类”),   API_Practice.PagedCharacters.Results(name:“ Abadango群集   公主”,状态:“活着”,物种:“外星人”),   API_Practice.PagedCharacters.Results(name:“ Abradolf Lincler”,状态:   “未知”,种类:“人类”),   API_Practice.PagedCharacters.Results(name:“ Adjudicator Rick”,状态:   “ Dead”,种类:“ Human”),API_Practice.PagedCharacters.Results(名称:   “代理总监”,状态:“死亡”,种类:“人类”),   API_Practice.PagedCharacters.Results(name:“ Alan Rails”,状态:   “ Dead”,种类:“ Human”),API_Practice.PagedCharacters.Results(名称:   “爱因斯坦(Albert Einstein)”,状态:“死亡”,物种:“人类”),   API_Practice.PagedCharacters.Results(name:“ Alexander”,状态:   “ Dead”,种类:“ Human”),API_Practice.PagedCharacters.Results(名称:   “ Alien Googah”,状态:“未知”,种类:“ Alien”),   API_Practice.PagedCharacters.Results(name:“ Alien Morty”,状态:   “未知”,种类:“外星人”),   API_Practice.PagedCharacters.Results(name:“ Alien Rick”,状态:   “未知”,种类:“外星人”),   API_Practice.PagedCharacters.Results(name:“ Amish Cyborg”,状态:   “ Dead”,种类:“ Alien”),API_Practice.PagedCharacters.Results(名称:   “ Annie”,状态:“活着”,物种:“人类”),   API_Practice.PagedCharacters.Results(名称:“天线莫蒂”,状态:   “ Alive”,种类:“ Human”),API_Practice.PagedCharacters.Results(名称:   “ Antenna Rick”,状态:“未知”,种类:“人类”),   API_Practice.PagedCharacters.Results(name:“ Ants in My Eyes Johnson”,   状态:“未知”,种类:“人类”)))

如果您还有其他需要,请告诉我。谢谢!

1 个答案:

答案 0 :(得分:1)

您的逻辑中有许多缺陷,因此我以最小的更改将其重写。现在它将满足您的目的。

import UIKit
struct PagedCharacters: Codable {
    let info: Info
    let results: [Results]

}
struct Info: Codable {
    let count: Int
    let pages: Int
    let next: String
    let prev: String
}

struct Results: Codable {
    let name: String
    let status: String
    let species: String
}

这是视图控制器类的代码:

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet var uiTableView: UITableView!
    var aryDownloadedData:[Results]?
    var nextPageUrl:String!

    override func viewDidLoad() {
        super.viewDidLoad()
        getIntitalRickAndMortyData()


        self.uiTableView.dataSource = self
        self.uiTableView.delegate = self

        // Do any additional setup after loading the view.
    }
    func getIntitalRickAndMortyData(){
        aryDownloadedData = []
        //here first page is next page
        nextPageUrl = "https://rickandmortyapi.com/api/character/"
        getRickAndMortyData()
    }

    func getRickAndMortyData() {

        //construct the url, use guard to avoid nonoptional
        guard let urlObj = URL(string: nextPageUrl) else
        { return }

        //fetch data
        URLSession.shared.dataTask(with: urlObj) {[weak self](data, response, error) in

            //to avoid non optional in JSONDecoder
            guard let data = data else { return }

            do {
                //decode object
                let downloadedRickAndMorty = try JSONDecoder().decode(PagedCharacters.self, from: data)
                self?.aryDownloadedData?.append(contentsOf: downloadedRickAndMorty.results)
                self?.nextPageUrl = downloadedRickAndMorty.info.next

                DispatchQueue.main.async {
                    self?.uiTableView.reloadData()
                }
                print(self?.aryDownloadedData as Any)

            } catch {
                print(error)

            }

            }.resume()

    }


    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.aryDownloadedData?.count ?? 0
    }

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

        if let count = aryDownloadedData?.count, count>1{
            let lastElement = count - 1
            if indexPath.row == lastElement {
                //call get api for next page
                getRickAndMortyData()
            }
        }

        guard let cell = tableView.dequeueReusableCell(withIdentifier: "rickandmortyCell") as? CharacterTableViewCell else { return UITableViewCell() }

        cell.nameLabel.text = "Name: " + (self.aryDownloadedData?[indexPath.row].name ?? "default")

        return cell
    }
}