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我正在製作一個簡單的新聞應用程序，並嘗試在NSUserDefaults中保存（標題，描述，日期，圖像及其數據）以供離線閱讀。我希望當它將數據保存在NSUserDefaults中時，它會在脫機狀態下顯示，並且當新數據可用時，它將重寫或替換之前的數據。 我知道如何將字符串數組保存在NSUserDefaults中，但沒有正確地知道如何將圖像保存在NSUserDefaults中。我試圖製作保存數據的邏輯，並檢查它是否有新的數據可用，但沒有成功，啓動屏幕需要更多時間才能消失，是由於從服務器加載數據還是由於互聯網連接速度慢？ 任何人都可以檢查我的代碼修復它。 感謝將XML數據保存在NSUserDefaults或文檔目錄中
class ViewController2: UIViewController ,NSXMLParserDelegate {
let newsDefaults = NSUserDefaults.standardUserDefaults()
@IBOutlet weak var tableView: UITableView!
var parser = NSXMLParser()
var posts = NSMutableArray()
var elements = NSMutableDictionary()
var element = NSString()
var title1 = NSMutableString()
var date = NSMutableString()
var link = NSMutableString()
var des = NSMutableString()
var img2 = NSMutableString()
var NSUserDefaultsTitle : [NSString] = []
var NSUserDefaultsDate : [NSString] = []
var NSUserDefaultsDes : [NSString] = []
var NSUserDefaultsImage : [UIImage] = []
typealias CompletionHandler = (image: UIImage) -> Void
var attrsUrl : [String : NSString]!
var urlPic : NSString?
var postLink: String = String()
override func viewDidLoad() {
super.viewDidLoad()
self.configure()
self.beginParsing()
}
override func viewWillAppear(animated: Bool) {
// if let HaveTitle = newsDefaults.objectForKey("t"){
// NSUserDefaultsTitle = HaveTitle.mutableCopy() as! [NSString]
// }
// if let HaveDate = newsDefaults.objectForKey("d"){
// NSUserDefaultsDate = HaveDate.mutableCopy() as! [NSString]
// }
// if let HaveDes = newsDefaults.objectForKey("des"){
// NSUserDefaultsDes = HaveDes.mutableCopy() as! [NSString]
// }
// if let imageData = newsDefaults.objectForKey("imgData"){
// NSUserDefaultsImage = imageData.mutableCopy() as! [UIImage]
// }
//
// print(newsDefaults.objectForKey("d"))
}
func beginParsing()
{
posts = []
parser = NSXMLParser(contentsOfURL:(NSURL(string: "http://www.voanews.com/api/zq$omekvi_"))!)!
parser.delegate = self
parser.parse()
tableView!.reloadData()
}
//XMLParser Methods
func parser(parser: NSXMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String])
{
element = elementName
if (elementName as NSString).isEqualToString("item")
{
elements = NSMutableDictionary()
elements = [:]
title1 = NSMutableString()
title1 = ""
date = NSMutableString()
date = ""
link = NSMutableString()
link = ""
des = NSMutableString()
des = ""
img2 = NSMutableString()
img2 = ""
}
if elementName == "enclosure" {
attrsUrl = attributeDict as [String: NSString]
urlPic = attrsUrl["url"]
print(urlPic!, terminator: "")
}
}
func parser(parser: NSXMLParser, didEndElement elementName: String, namespaceURI: String?, qualifiedName qName: String?)
{
if (elementName as NSString).isEqualToString("item") {
if !title1.isEqual(nil) {
elements.setObject(title1, forKey: "title")
}
if !date.isEqual(nil) {
elements.setObject(date, forKey: "pubDate")
}
if !link.isEqual(nil) {
elements.setObject(link, forKey: "link")
}
if !des.isEqual(nil){
elements.setObject(des, forKey: "description")
}
if !img2.isEqual(nil){
elements.setObject(urlPic!, forKey: "enclosure")
}
posts.addObject(elements)
//
// if let HaveData = newsDefaults.objectForKey("post"){
//
// }else{
//
//// newsDefaults.setObject(self.posts.valueForKey("title"), forKey: "t")
//// newsDefaults.setObject(self.posts.valueForKey("pubDate"), forKey: "d")
//// newsDefaults.setObject(self.posts.valueForKey("description"), forKey: "des")
//
// newsDefaults.setObject(posts, forKey: "post")
//
print("elementName")
// }
}
print("didEndElement")
}
func parser(parser: NSXMLParser, foundCharacters string: String)
{
if element.isEqualToString("title") {
title1.appendString(string)
} else if element.isEqualToString("pubDate") {
date.appendString(string)
print(date)
}
else if element.isEqualToString("link"){
link.appendString(string)
}else if element.isEqualToString("description"){
des.appendString(string)
}else if element.isEqualToString("enclosure"){
img2.appendString(string)
}
print("foundCharacter")
}
private func configure() {
self.navigationController?.navigationBar.titleTextAttributes = [NSFontAttributeName: UIFont.boldSystemFontOfSize(20.0), NSForegroundColorAttributeName: UIColor.whiteColor()]
self.tableView.registerNib(UINib(nibName: "2ImageCell", bundle: nil), forCellReuseIdentifier: "imageCell")
self.tableView.delegate = self
self.tableView.dataSource = self
self.fillNavigationBar(color: UIColor(red: 252.0/255.0, green: 0, blue: 0, alpha: 1.0))
}
private func fillNavigationBar(color color: UIColor) {
if let nav = self.navigationController {
nav.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: .Default)
nav.navigationBar.shadowImage = UIImage()
for view in nav.navigationBar.subviews {
if view.isKindOfClass(NSClassFromString("_UINavigationBarBackground")!) {
if view.isKindOfClass(UIView) {
(view as UIView).backgroundColor = color
}
}
}
}
}
}
extension ViewController2: UITableViewDelegate, UITableViewDataSource {
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
self.tableView.deselectRowAtIndexPath(indexPath, animated: true)
let view = ImageModalView2.instantiateFromNib()
view.des.text = posts.objectAtIndex(indexPath.row).valueForKey("description") as? String
downloadFileFromURL(NSURL(string: self.posts.objectAtIndex(indexPath.row).valueForKey("enclosure") as! String)!, completionHandler:{(img) in
dispatch_async(dispatch_get_main_queue(), {() -> Void in
view.image = img
})
})
let window = UIApplication.sharedApplication().delegate?.window!
let modal = PathDynamicModal.show(modalView: view, inView: window!)
view.closeButtonHandler = {[weak modal] in
modal?.closeWithLeansRandom()
return
}
}
@IBAction func printData(sender: AnyObject) {
print(NSUserDefaultsImage)
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 80.0
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return posts.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = self.tableView.dequeueReusableCellWithIdentifier("imageCell", forIndexPath: indexPath) as! ImageCell2
// if let picURL = user["picture"].string, url = NSURL(string: picURL) {
// if let data = NSData(contentsOfURL: url) {
// cell!.imageView?.image = UIImage(data: data)
// }
cell.titleLabel.text = posts.objectAtIndex(indexPath.row).valueForKey("title") as! NSString as String
// if NSUserDefaultsImage {
// cell.sideImageView.image = NSUserDefaultsImage[indexPath.row]
// }else{
downloadFileFromURL(NSURL(string: self.posts.objectAtIndex(indexPath.row).valueForKey("enclosure") as! String)!, completionHandler:{(img) in
dispatch_async(dispatch_get_main_queue(), {() -> Void in
cell.sideImageView.image = img
// self.NSUserDefaultsImage.append(img)
// print(img)
// self.newsDefaults.setObject(self.NSUserDefaultsImage, forKey: "imgData")
})
})
// }
//cell.date.text = posts.objectAtIndex(indexPath.row).valueForKey("pubDate") as? String
//cell.sideImageView?.contentMode = UIViewContentMode.ScaleAspectFit
//cell.sideImageView?.image = image
cell.titleLabel.userInteractionEnabled = false
cell.titleLabel.editable = false
cell.titleLabel.selectable = false
return cell
}
func downloadFileFromURL(url1: NSURL?,completionHandler: CompletionHandler) {
// download code.
if let url = url1{
let priority = DISPATCH_QUEUE_PRIORITY_HIGH
dispatch_async(dispatch_get_global_queue(priority, 0)) {
let data = NSData(contentsOfURL: url)
if data != nil {
print("image downloaded")
completionHandler(image: UIImage(data: data!)!)
}
}
}
}
}