细节

Xcode版本10.3 (10G8)， Swift 5

特性

能够使“拉刷新”编程 保护从多个“拉刷新”事件 当视图控制器切换(例如在TabController的情况下)时，继续动画活动指示器的能力

解决方案

import UIKit

class RefreshControl: UIRefreshControl {

    private weak var actionTarget: AnyObject?
    private var actionSelector: Selector?
    override init() { super.init() }

    convenience init(actionTarget: AnyObject?, actionSelector: Selector) {
        self.init()
        self.actionTarget = actionTarget
        self.actionSelector = actionSelector
        addTarget()
    }

    private func addTarget() {
        guard let actionTarget = actionTarget, let actionSelector = actionSelector else { return }
        addTarget(actionTarget, action: actionSelector, for: .valueChanged)
    }

    required init?(coder aDecoder: NSCoder) { super.init(coder: aDecoder) }

    func endRefreshing(deadline: DispatchTime? = nil) {
        guard let deadline = deadline else { endRefreshing(); return }
        DispatchQueue.global(qos: .default).asyncAfter(deadline: deadline) { [weak self] in
            DispatchQueue.main.async { self?.endRefreshing() }
        }
    }

    func refreshActivityIndicatorView() {
        guard let selector = actionSelector else { return }
        let _isRefreshing = isRefreshing
        removeTarget(actionTarget, action: selector, for: .valueChanged)
        endRefreshing()
        if _isRefreshing { beginRefreshing() }
        addTarget()
    }

    func generateRefreshEvent() {
        beginRefreshing()
        sendActions(for: .valueChanged)
    }
}

public extension UIScrollView {

    private var _refreshControl: RefreshControl? { return refreshControl as? RefreshControl }

    func addRefreshControll(actionTarget: AnyObject?, action: Selector, replaceIfExist: Bool = false) {
        if !replaceIfExist && refreshControl != nil { return }
        refreshControl = RefreshControl(actionTarget: actionTarget, actionSelector: action)
    }

    func scrollToTopAndShowRunningRefreshControl(changeContentOffsetWithAnimation: Bool = false) {
        _refreshControl?.refreshActivityIndicatorView()
        guard   let refreshControl = refreshControl,
                contentOffset.y != -refreshControl.frame.height else { return }
        setContentOffset(CGPoint(x: 0, y: -refreshControl.frame.height), animated: changeContentOffsetWithAnimation)
    }

    private var canStartRefreshing: Bool {
        guard let refreshControl = refreshControl, !refreshControl.isRefreshing else { return false }
        return true
    }

    func startRefreshing() {
        guard canStartRefreshing else { return }
        _refreshControl?.generateRefreshEvent()
    }

    func pullAndRefresh() {
        guard canStartRefreshing else { return }
        scrollToTopAndShowRunningRefreshControl(changeContentOffsetWithAnimation: true)
        _refreshControl?.generateRefreshEvent()
    }

    func endRefreshing(deadline: DispatchTime? = nil) { _refreshControl?.endRefreshing(deadline: deadline) }
}

使用

// Add refresh control to UICollectionView / UITableView / UIScrollView
private func setupTableView() {
    let tableView = UITableView()
    // ...
    tableView.addRefreshControll(actionTarget: self, action: #selector(refreshData))
}

@objc func refreshData(_ refreshControl: UIRefreshControl) {
    tableView?.endRefreshing(deadline: .now() + .seconds(3))
}

// Stop refreshing in UICollectionView / UITableView / UIScrollView
tableView.endRefreshing()

// Simulate pull to refresh in UICollectionView / UITableView / UIScrollView
tableView.pullAndRefresh()

完整的样品

不要忘记在这里添加解决方案代码

import UIKit

class ViewController: UIViewController {

    private weak var tableView: UITableView?

    override func viewDidLoad() {
        super.viewDidLoad()
        setupTableView()
    }

    private func setupTableView() {
        let tableView = UITableView()
        view.addSubview(tableView)
        tableView.translatesAutoresizingMaskIntoConstraints = false
        tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
        tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
        tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        tableView.dataSource = self
        tableView.delegate = self
        tableView.addRefreshControll(actionTarget: self, action: #selector(refreshData))
        self.tableView = tableView
    }
}

extension ViewController {
    @objc func refreshData(_ refreshControl: UIRefreshControl) {
        print("refreshing")
        tableView?.endRefreshing(deadline: .now() + .seconds(3))
    }
}

extension ViewController: UITableViewDataSource {
    func numberOfSections(in tableView: UITableView) -> Int { return 1 }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return 20 }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell()
        cell.textLabel?.text = "\(indexPath)"
        return cell
    }
}

extension ViewController: UITableViewDelegate {
    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        tableView.pullAndRefresh()
    }
}

我构建了一个RSS提要应用程序，在其中我有一个Pull To refresh功能，它最初有上面列出的一些问题。

但是为了补充上面用户的答案，我到处寻找我的用例，但没有找到它。我正在从网络(RSSFeed)下载数据，我想下拉我的故事tableView来刷新。

上面提到的内容涵盖了正确的领域，但人们遇到了一些问题，以下是我所做的，它很有效:

我采取了@Blankarsch的方法，去了我的主。然后选择表视图来使用刷新，然后没有提到的是创建IBOutlet和IBAction来有效地使用刷新

//Created from main.storyboard cntrl+drag refresh from left scene to assistant editor @IBOutlet weak var refreshButton: UIRefreshControl override func viewDidLoad() { ...... ...... //Include your code ...... ...... //Is the function called below, make sure to put this in your viewDidLoad //method or not data will be visible when running the app getFeedData() } //Function the gets my data/parse my data from the web (if you havnt already put this in a similar function) //remembering it returns nothing, hence return type is "-> Void" func getFeedData() -> Void{ ..... ..... } //From main.storyboard cntrl+drag to assistant editor and this time create an action instead of outlet and //make sure arguments are set to none and note sender @IBAction func refresh() { //getting our data by calling the function which gets our data/parse our data getFeedData() //note: refreshControl doesnt need to be declared it is already initailized. Got to love xcode refreshControl?.endRefreshing() }

希望这能帮助到和我处境相同的人

您可以通过使用几行代码来实现这一点。所以为什么你会困在第三方库或UI中。 拉动刷新是iOS内置的。你可以像这样快速完成

var pullControl = UIRefreshControl()

override func viewDidLoad() {
   super.viewDidLoad()

   pullControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
   pullControl.addTarget(self, action: #selector(pulledRefreshControl(_:)), for: UIControl.Event.valueChanged)
   tableView.addSubview(pullControl) // not required when using UITableViewController
}

@objc func pulledRefreshControl(sender:AnyObject) {
   // Code to refresh table view  
}

func pullToRefresh(){

    let refresh = UIRefreshControl()
    refresh.addTarget(self, action: #selector(handleTopRefresh(_:)), for: .valueChanged )
    refresh.tintColor = UIColor.appBlack
    self.tblAddressBook.addSubview(refresh)

}
@objc func handleTopRefresh(_ sender:UIRefreshControl){
    self.callAddressBookListApi(isLoaderRequired: false)
    sender.endRefreshing()
}

这就是我如何使用Xcode 7.2让它工作的，我认为这是一个主要的错误。我在我的UITableViewController中使用它在viewWillAppear中

refreshControl = UIRefreshControl()
refreshControl!.addTarget(self, action: "configureMessages", forControlEvents: .ValueChanged)
refreshControl!.beginRefreshing()

configureMessages()

func configureMessages() {
    // configuring messages logic here

    self.refreshControl!.endRefreshing()
}

正如你所看到的，我必须在设置我的UIRefreshControl之后调用configureMessage()方法，随后的刷新将正常工作。

我建议在每个类中使用pull to Refresh的扩展。

1)创建一个空的swift文件:文件-新建-文件- swift文件。

2)添加以下内容

    //  AppExtensions.swift

    import Foundation
    import UIKit    

    var tableRefreshControl:UIRefreshControl = UIRefreshControl()    

    //MARK:- VIEWCONTROLLER EXTENSION METHODS
    public extension UIViewController
    {
        func makePullToRefreshToTableView(tableName: UITableView,triggerToMethodName: String){

            tableRefreshControl.attributedTitle = NSAttributedString(string: "TEST: Pull to refresh")
            tableRefreshControl.backgroundColor = UIColor.whiteColor()
            tableRefreshControl.addTarget(self, action: Selector(triggerToMethodName), forControlEvents: UIControlEvents.ValueChanged)
            tableName.addSubview(tableRefreshControl)
        }
        func makePullToRefreshEndRefreshing (tableName: String)
        {
            tableRefreshControl.endRefreshing()
//additional codes

        }
    }    

3)在你的视图控制器中调用这些方法:

  override func viewWillAppear(animated: Bool) {

self.makePullToRefreshToTableView(bidderListTable, triggerToMethodName: "pullToRefreshBidderTable")
}

4)在某些时候，你想要结束刷新:

  func pullToRefreshBidderTable() {
self.makePullToRefreshEndRefreshing("bidderListTable")    
//Code What to do here.
}
OR    
self.makePullToRefreshEndRefreshing("bidderListTable")