swift - 使用 swift 在 CloudKit 中加载更多内容

Question

我有 2 个函数 loadData 和 loadMore 如下:

import UIKit
import CloudKit

class HireView: UIViewController, UITableViewDelegate, UITableViewDataSource, UIGestureRecognizerDelegate, UIScrollViewDelegate, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource, UIPickerViewDelegate, UIPickerViewDataSource {

    @IBOutlet weak var tableView: UITableView!
    let myData = CKContainer.default().publicCloudDatabase
    let predicate = NSPredicate(value: true)

    override func viewDidLoad() {
        super.viewDidLoad()
        self.loadData()    
    }

    func loadData(){
        var result = [CKRecord]()
        let query = CKQuery(recordType: "Hire", predicate: predicate)
        query.sortDescriptors = [NSSortDescriptor(key: "postDate", ascending: false)]
        let operation = CKQueryOperation(query: query)
        operation.resultsLimit = 100
        operation.qualityOfService = .userInteractive
        operation.recordFetchedBlock = { (record) in
            DispatchQueue.main.async {
                result.append(record)
                hireItems = result
                self.tableView.reloadData()
            }
        }
        operation.queryCompletionBlock = { (cursor, error) in
            if error != nil {

            } else {
                if result.isEmpty == true {
                    DispatchQueue.main.async {
                        hireItems = result
                        self.tableView.reloadData()
                    }
                }
                DispatchQueue.main.async {
                self.tableView.reloadData()
            }
        }
    }
    myData.add(operation)
    }

    func loadMore(){
        let query = CKQuery(recordType: "Hire", predicate: predicate)
        query.sortDescriptors = [NSSortDescriptor(key: "postDate", ascending: false)]
        let operation = CKQueryOperation(query: query)
        operation.resultsLimit = hireItems.count + 100
        operation.qualityOfService = .userInteractive
        operation.recordFetchedBlock = { (record) in
            if (record["postDate"] as! Date) < (hireItems[hireItems.count - 1]["postDate"] as! Date) {
                DispatchQueue.main.async {
                    hireItems.append(record)
                    self.tableView.reloadData()
                }
            }
        }
        operation.queryCompletionBlock = { (cursor, error) in
            if error != nil {
                DispatchQueue.main.async {                            
                }
            } else {
                DispatchQueue.main.async {
                    self.tableView.reloadData()
                }
            }
        }
        myData.add(operation)
    }
}

我的问题是:

loadMore() 函数是最好的吗？有什么方法可以让 loadMore() 更好吗？

Answer 1

更好的方法可以使用 CKQueryCursor在 CKQueryOperation 的 queryCompletionBlock 中返回。

如果此游标不是nil，那么您还有更多记录等待获取。要继续获取，您应该使用 init(cursor: CKQueryCursor)初始化器。

Use this method to initialize a query operation that retrieves the next batch of results from a previous search.