我正在使用swift构建一个RSS阅读器,需要实现pull to reload功能。
这是我试图这样做的方式。
class FirstViewController: UIViewController,
UITableViewDelegate, UITableViewDataSource {
@IBOutlet var refresh: UIScreenEdgePanGestureRecognizer
@IBOutlet var newsCollect: UITableView
var activityIndicator:UIActivityIndicatorView? = nil
override func viewDidLoad() {
super.viewDidLoad()
self.newsCollect.scrollEnabled = true
// Do any additional setup after loading the view, typically from a nib.
if nCollect.news.count <= 2{
self.collectNews()
}
else{
self.removeActivityIndicator()
}
view.addGestureRecognizer(refresh)
}
@IBAction func reload(sender: UIScreenEdgePanGestureRecognizer) {
nCollect.news = News[]()
return newsCollect.reloadData()
}
我正进入(状态 :
属性'self.refresh'未在super.init调用中初始化
请帮助我理解手势识别器的行为。一个工作示例代码将是一个很好的帮助。
谢谢。
Pull to refresh是在iOS中构建的。你可以像swift那样做
var refreshControl = UIRefreshControl()
override func viewDidLoad() {
super.viewDidLoad()
refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
refreshControl.addTarget(self, action: #selector(refresh(_:)), for: UIControl.Event.valueChanged)
tableView.addSubview(refreshControl) // not required when using UITableViewController
}
@objc func refresh(sender:AnyObject) {
// Code to refresh table view
}
在某些时候,你可以结束刷新。
refreshControl.endRefreshing()
我建议在每个班级中使用pull To Refresh扩展。
1)制作一个空的swift文件:File - New - File - Swift File。
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View Controller中将这些方法称为:
override func viewWillAppear(animated: Bool) {
self.makePullToRefreshToTableView(bidderListTable, triggerToMethodName: "pullToRefreshBidderTable")
}
4)在某些时候你想结束刷新:
func pullToRefreshBidderTable() {
self.makePullToRefreshEndRefreshing("bidderListTable")
//Code What to do here.
}
OR
self.makePullToRefreshEndRefreshing("bidderListTable")
为了刷新我正在使用
DGElasticPullToRefresh
https://github.com/gontovnik/DGElasticPullToRefresh
安装
在'DGElasticPullToRefresh'下
import DGElasticPullToRefresh
并将此函数放入您的swift文件并从您的调用此函数
覆盖func viewWillAppear(_ animated:Bool)
func Refresher() {
let loadingView = DGElasticPullToRefreshLoadingViewCircle()
loadingView.tintColor = UIColor(red: 255.0/255.0, green: 255.0/255.0, blue: 255.0/255.0, alpha: 1.0)
self.table.dg_addPullToRefreshWithActionHandler({ [weak self] () -> Void in
//Completion block you can perfrom your code here.
print("Stack Overflow")
self?.table.dg_stopLoading()
}, loadingView: loadingView)
self.table.dg_setPullToRefreshFillColor(UIColor(red: 255.0/255.0, green: 57.0/255.0, blue: 66.0/255.0, alpha: 1))
self.table.dg_setPullToRefreshBackgroundColor(self.table.backgroundColor!)
}
并且不要忘记删除引用,而视图将消失
删除pull以刷新将此代码放入您的
覆盖func viewDidDisappear(_ animated:Bool)
override func viewDidDisappear(_ animated: Bool) {
table.dg_removePullToRefresh()
}
它看起来会像
快乐编码:)
你可以使用tableView的这个子类:
import UIKit
protocol PullToRefreshTableViewDelegate : class {
func tableViewDidStartRefreshing(tableView: PullToRefreshTableView)
}
class PullToRefreshTableView: UITableView {
@IBOutlet weak var pullToRefreshDelegate: AnyObject?
private var refreshControl: UIRefreshControl!
private var isFirstLoad = true
override func willMoveToSuperview(newSuperview: UIView?) {
super.willMoveToSuperview(newSuperview)
if (isFirstLoad) {
addRefreshControl()
isFirstLoad = false
}
}
private func addRefreshControl() {
refreshControl = UIRefreshControl()
refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
refreshControl.addTarget(self, action: "refresh", forControlEvents: .ValueChanged)
self.addSubview(refreshControl)
}
@objc private func refresh() {
(pullToRefreshDelegate as? PullToRefreshTableViewDelegate)?.tableViewDidStartRefreshing(self)
}
func endRefreshing() {
refreshControl.endRefreshing()
}
}
1 - 在界面构建器中将tableView的类更改为PullToRefreshTableView
或以编程方式创建PullToRefreshTableView
2 - 在视图控制器中实现PullToRefreshTableViewDelegate
3 - 当表视图开始刷新时,将在视图控制器中调用tableViewDidStartRefreshing(tableView: PullToRefreshTableView)
4 - 打电话给yourTableView.endRefreshing()
完成清爽
这就是我使用Xcode 7.2工作的方式,我认为这是一个主要的错误。我在我的UITableViewController
里面的viewWillAppear
里面使用它
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,我确实必须在设置我的configureMessage()
之后调用UIRefreshControl
方法然后在那之后,随后的刷新将正常工作。
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) }
}
// 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()
不要忘记在此处添加解决方案代码
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()
}
}
其他答案是正确的但更多细节检查此帖Pull to Refresh
在Storyboard中启用刷新
当您使用UITableViewController时,解决方案非常简单:首先,在故事板中选择表视图控制器,打开属性检查器,然后启用刷新:
UITableViewController配备了一个开箱即用的UIRefreshControl引用。您只需要连接一些内容即可在用户下拉时启动并完成刷新。
覆盖viewDidLoad()
在覆盖viewDidLoad()时,添加目标以处理刷新,如下所示:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.refreshControl?.addTarget(self, action: "handleRefresh:", forControlEvents: UIControlEvents.ValueChanged)
}
refreshControl.endRefreshing()
欲了解更多信息,请参阅链接,所有信用都转到该帖子
故事板和快速解决方案......
1.)打开.storyboard文件,在故事板中选择TableViewController,并在“实用程序”中“启用”表视图控制器 - 刷新功能。
2.)打开关联的UITableViewController-Class并将以下行添加到viewDidLoad-Method中。
self.refreshControl?.addTarget(self, action: "refresh:", forControlEvents: UIControlEvents.ValueChanged)
编辑Swift 5.0:
self.refreshControl?.addTarget(self, action: #selector(refresh), for: UIControl.Event.valueChanged)
或者在Swift 2.2中:
self.refreshControl?.addTarget(self, action: #selector(TestTableViewController.refresh(_:)), forControlEvents: UIControlEvents.ValueChanged)
3.)在viewDidLoad-Method上方添加以下方法
func refresh(sender:AnyObject)
{
// Updating your data here...
self.tableView.reloadData()
self.refreshControl?.endRefreshing()
}
我想提一下自iOS 10以来一直包含的PRETTY COOL功能,它是:
目前,UIRefreshControl直接支持UICollectionView
,UITableView
和UIScrollView
!
这些视图中的每一个都有refreshControl实例属性,这意味着不再需要在滚动视图中将其添加为子视图,您所要做的就是:
@IBOutlet weak var collectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
let refreshControl = UIRefreshControl()
refreshControl.addTarget(self, action: #selector(doSomething), for: .valueChanged)
// this is the replacement of implementing: "collectionView.addSubview(refreshControl)"
collectionView.refreshControl = refreshControl
}
func doSomething(refreshControl: UIRefreshControl) {
print("Hello World!")
// somewhere in your code you might need to call:
refreshControl.endRefreshing()
}
就个人而言,我觉得将它作为滚动视图的属性处理比将其添加为子视图更自然,特别是因为作为UIRefreshControl的超级视图的唯一合适的视图是滚动视图,即使用UIRefreshControl的功能仅是使用滚动视图时很有用;这就是为什么这种方法应该更明显地设置刷新控制视图。
但是,您仍然可以选择使用基于iOS版本的addSubview
:
if #available(iOS 10.0, *) {
collectionView.refreshControl = refreshControl
} else {
collectionView.addSubview(refreshControl)
}
斯威夫特4
var refreshControl: UIRefreshControl!
override func viewDidLoad() {
super.viewDidLoad()
refreshControl = UIRefreshControl()
refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
refreshControl.addTarget(self, action: #selector(refresh), for: .valueChanged)
tableView.addSubview(refreshControl)
}
@objc func refresh(_ sender: Any) {
// your code to refresh tableView
}
你可以停止刷新:
refreshControl.endRefreshing()
在Swift中使用它,
如果您想在WebView中进行刷新,
所以尝试这个代码:
override func viewDidLoad() {
super.viewDidLoad()
addPullToRefreshToWebView()
}
func addPullToRefreshToWebView(){
var refreshController:UIRefreshControl = UIRefreshControl()
refreshController.bounds = CGRectMake(0, 50, refreshController.bounds.size.width, refreshController.bounds.size.height) // Change position of refresh view
refreshController.addTarget(self, action: Selector("refreshWebView:"), forControlEvents: UIControlEvents.ValueChanged)
refreshController.attributedTitle = NSAttributedString(string: "Pull down to refresh...")
YourWebView.scrollView.addSubview(refreshController)
}
func refreshWebView(refresh:UIRefreshControl){
YourWebView.reload()
refresh.endRefreshing()
}
安希尔的回答对我很有帮助。
然而,经过进一步的实验,我注意到建议的解决方案有时会导致一个不那么漂亮的UI glitch。
相反,前往this approach *为我做了伎俩。
//Create an instance of a UITableViewController. This will host your UITableView.
private let tableViewController = UITableViewController()
//Add tableViewController as a childViewController and set its tableView property to your UITableView.
self.addChildViewController(self.tableViewController)
self.tableViewController.tableView = self.tableView
self.refreshControl.addTarget(self, action: "refreshData:", forControlEvents: .ValueChanged)
self.tableViewController.refreshControl = self.refreshControl
错误告诉你的是,refresh
没有初始化。请注意,您选择使refresh
不是可选的,在Swift中意味着它必须在调用super.init
之前有一个值(或者它被隐式调用,这似乎是你的情况)。要么使refresh
可选(可能是你想要的)或以某种方式初始化它。
我建议再次阅读Swift介绍性文档,其中包含了很长的内容。
最后一点,不是答案的一部分,正如@Anil所指出的那样,在iOS中有一个内置的刷新控制叫做UIRefresControl
,这可能是值得研究的东西。
我构建了一个RSS feed应用程序,其中我有一个Pull To刷新功能,最初有一些上面列出的问题。
但是为了向用户添加上面的答案,我到处寻找我的用例并找不到它。我正在从网上下载数据(RSSFeed),我想要下载我的tableView故事刷新。
上面提到的内容涵盖了正确的领域,但是由于人们遇到了一些问题,这就是我所做的,它的作用是:
我采用@Blankarsch的方法并转到我的main.storyboard并选择表视图以使用refresh,然后未提及的是创建IBOutlet和IBAction以有效地使用刷新
//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()
}
希望这能帮助任何与我相同情况的人
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()
}