Question

我有2个函数loadData和loadMore，如下所示：

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()功能最好吗？有没有办法让loadMore()更好？

Answer 1

更好的方法可能是使用CKQueryOperation queryCompletionBlock中返回的CKQueryCursor。

如果此光标不是nil，那么您将有更多记录等待获取。要继续抓取，您应该使用init(cursor: CKQueryCursor)初始值设定项。

使用此方法初始化检索的查询操作上一次搜索的下一批结果。

使用swift在CloudKit中加载更多内容

1 个答案: