在 tableView 上拉刷新
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【中文标题】在 tableView 上拉刷新【英文标题】：Pull to Refresh on tableView 【发布时间】：2017-07-19 12:10:07 【问题描述】：我想拉刷新我的 RSS 提要新闻应用程序。我使用导航控制器和表格视图控制器。在 Table View Controller 上我应该怎么做？我们应该添加什么？我的代码在这里。
class TableviewController: UITableViewController
var items : Array<Item> = []
var entries : Array<Entry> = []
override func viewDidLoad()
super.viewDidLoad()
loadRSS()
loadAtom()
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
return items.count
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
let cell = tableView.dequeueReusableCell(withIdentifier: "ItemCell", for: indexPath)
let item:Item = self.items[indexPath.row]
cell.textLabel?.text = item.title
cell.detailTextLabel?.text = self.pubDateStringFromDate(item.pubDate! as Date)
return cell
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
let item = self.items[indexPath.row]
let url:URL = URL(string: item.link!)!
let safariViewController = SFSafariViewController(url: url, entersReaderIfAvailable: true)
present(safariViewController, animated: true, completion: nil)
func loadRSS()
let feedUrlString:String = "websiteurl"
Alamofire.request(feedUrlString).response response in
if let data = response.data, let _ = String(data: data, encoding: .utf8)
TIFeedParser.parseRSS(xmlData: data as NSData, completionHandler: (isSuccess, channel, error) -> Void in
if (isSuccess)
self.items = channel!.items!
self.tableView.reloadData()
if (response.error != nil)
print((response.error?.localizedDescription)! as String)
)
func loadAtom()
let feedUrlString:String = "websiteurl"
Alamofire.request(feedUrlString).response response in
if let data = response.data, let _ = String(data: data, encoding: .utf8)
TIFeedParser.parseAtom(xmlData: data as NSData, completionHandler: (isSuccess, feed, error) -> Void in
if (isSuccess)
self.entries = feed!.entries!
self.tableView.reloadData()
if (error != nil)
print((error?.localizedDescription)! as String)
)
func pubDateStringFromDate(_ pubDate:Date)->String
let format = DateFormatter()
format.dateFormat = "yyyy/M/d HH:mm"
let pubDateString = format.string(from: pubDate)
return pubDateString
【问题讨论】：
【参考方案1】：1) 将UIRefreshControl 类型的属性声明为：
var refreshControl = UIRefreshControl()
2) 在viewDidLoad()method 中，将此 refreshControl 添加到您的表格视图中：
self.refreshControl.addTarget(self, action: #selector(loadRSS), for: .valueChanged)
if #available(ios 10, *)
self.tableView.refreshControl = self.refreshControl
else
self.tableView.addSubview(self.refreshControl)
【讨论】：
【参考方案2】：在 TableViewController 中声明一个属性 refreshControl 为
var refreshControl:UIRefreshControl?
在viewDidLoad()函数中添加如下代码
refreshControl?.addTarget(self, action: #selector(loadRSS), for: .valueChanged)
self.tableView.addSubview(refreshControl!)
将您的 loadRSS() 函数更新为
func loadRSS()
let feedUrlString:String = "websiteurl"
Alamofire.request(feedUrlString).response response in
self.refreshControl?.endRefreshing(
if let data = response.data, let _ = String(data: data, encoding: .utf8)
TIFeedParser.parseRSS(xmlData: data as NSData, completionHandler: (isSuccess, channel, error) -> Void in
if (isSuccess)
self.items = channel!.items!
self.tableView.reloadData()
if (response.error != nil)
print((response.error?.localizedDescription)! as String)
)
【讨论】：
【参考方案3】：请参考以下代码，因为我在您的代码上添加了拉动刷新控制。
class TableviewController: UITableViewController
var items : Array<Item> = []
var entries : Array<Entry> = []
var pullToFrefreshNews:UIRefreshControl!
override func viewDidLoad()
super.viewDidLoad()
loadRSS()
loadAtom()
self.addPulltoRefrehs()
func addPulltoRefrehs()
self.pullToFrefreshNews = UIRefreshControl()
self.pullToFrefreshNews.addTarget(self, action: #selector(TableviewController.loadRSS), for: UIControlEvents.valueChanged)
self.newsTableVU.addSubview(pullToFrefreshNews)
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
return items.count
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
let cell = tableView.dequeueReusableCell(withIdentifier: "ItemCell", for: indexPath)
let item:Item = self.items[indexPath.row]
cell.textLabel?.text = item.title
cell.detailTextLabel?.text = self.pubDateStringFromDate(item.pubDate! as Date)
return cell
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
let item = self.items[indexPath.row]
let url:URL = URL(string: item.link!)!
let safariViewController = SFSafariViewController(url: url, entersReaderIfAvailable: true)
present(safariViewController, animated: true, completion: nil)
func loadRSS()
let feedUrlString:String = "websiteurl"
Alamofire.request(feedUrlString).response response in
if let data = response.data, let _ = String(data: data, encoding: .utf8)
TIFeedParser.parseRSS(xmlData: data as NSData, completionHandler: (isSuccess, channel, error) -> Void in
if (isSuccess)
self.items = channel!.items!
self.tableView.reloadData()
if (response.error != nil)
print((response.error?.localizedDescription)! as String)
)
func loadAtom()
let feedUrlString:String = "websiteurl"
Alamofire.request(feedUrlString).response response in
if let data = response.data, let _ = String(data: data, encoding: .utf8)
TIFeedParser.parseAtom(xmlData: data as NSData, completionHandler: (isSuccess, feed, error) -> Void in
if (isSuccess)
self.entries = feed!.entries!
self.tableView.reloadData()
if (error != nil)
print((error?.localizedDescription)! as String)
)
func pubDateStringFromDate(_ pubDate:Date)->String
let format = DateFormatter()
format.dateFormat = "yyyy/M/d HH:mm"
let pubDateString = format.string(from: pubDate)
return pubDateString
【讨论】：
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