如何在 iOS 应用中为 YouTube Data API V3 实现分页

Question

我正在使用 Youtube 数据 API 构建一个 iOS 应用程序，它获取频道的播放列表并将其显示在表格视图中。但问题是我最多只能获得 50 个播放列表结果。但播放列表的实际数量超过100.当我用谷歌搜索它时，我发现应该完成额外的结果分页。如何在 iOS 应用程序中添加分页以在表格视图中显示整个播放列表。如果我想使用 nextpage 令牌发出另一个请求，那么应该如何我做了它，应该修改代码的哪一部分。我使用 API 密钥而不是 OAuth

ViewController 代码

import UIKit

class ViewController: UIViewController,UITableViewDelegate,UITableViewDataSource {
   
    

    @IBOutlet weak var coursesTV: UITableView!
    
    var a = [Item]()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        
        coursesTV.delegate = self
        coursesTV.dataSource = self
        
        Playlist.sharedObj.getPlayList { (i) in
            self.a = i
            
            DispatchQueue.main.async {
                 self.coursesTV.reloadData()
            }
           
        }
        
        
    }
    
    
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        
        
        return a.count
           
       }
       
       func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
           
        if let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
        {
            cell.textLabel?.text = a[indexPath.row].snippet!.title!
            
            return cell
        }
        
        return UITableViewCell()
        
        
       }
}

网络服务结构

import Foundation

public  struct Playlist
{
   public static let sharedObj = Playlist()

    let playlistuRL = "URL_HERE"
    
    
    let session = URLSession(configuration: .default)
    
    
    func getPlayList(onSuccess:@escaping([Item])-> Void)
    {
            let task = self.session.dataTask(with: URL(string: self.playlistuRL)!) { (data, response, error) in
                    
                    do
                {
        
                        let item = try JSONDecoder().decode(RootClass.self, from: data!)
                        
                        print(item.items!.first!.snippet!.title!)
                        
                        onSuccess(item.items)
                    }
                    
                    catch
                    {
                        print(error)
                    }
                    
                    
                    
                }
                
                
                task.resume()
        
    }
}

模型结构

import Foundation


public struct RootClass: Codable {

        public var etag : String!
        public var items : [Item]!
        public var kind : String!
        public var nextPageToken : String!
        public var pageInfo : PageInfo!
        
}


public struct Default: Codable {

        public var height : Int!
        public var url : String!
        public var width : Int!
        
}

public struct High: Codable {

        public var height : Int!
        public var url : String!
        public var width : Int!
        
}

public struct Item: Codable {

        public var etag : String!
        public var id : String!
        public var kind : String!
        public var snippet : Snippet!
        
}

public struct Localized: Codable {

        public var descriptionField : String!
        public var title : String!
        
}

public struct Medium: Codable {

        public var height : Int!
        public var url : String!
        public var width : Int!
        
}

public struct PageInfo: Codable {

        public var resultsPerPage : Int!
        public var totalResults : Int!
        
}


public struct Snippet: Codable {

        public var channelId : String!
        public var channelTitle : String!
        public var descriptionField : String!
        public var localized : Localized!
        public var publishedAt : String!
        public var thumbnails : Thumbnail!
        public var title : String!
        
}

public struct Standard: Codable {

        public var height : Int!
        public var url : String!
        public var width : Int!
        
}


public struct Thumbnail: Codable {

        public var defaultField : Default!
        public var high : High!
        public var medium : Medium!
        public var standard : Standard!
        
}

Answer 1

基本上你必须为 tableview 实现加载更多概念。当您到达表中的最后一行时，发出 api 请求。 Youtube API 提供了 NextPageToken 和 PreviousPageToken 作为响应，所以你可以在到达最后一行时使用 NextPageToken 发出 api 请求。

示例代码sn-p：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text=[self.array objectAtIndex:indexPath.row];
if (indexPath.row ==[array count] -1 ) { //this method will get called when you will scroll to the bottom of your table view 
    [self sendAPIRequestMethod];  } return cell; }