The images from the webservice are refreshed in the UITableview - ios

Question

I was trying to load images from a web service to my tableview. But the images are refreshed and same image rotate in every cell. I think the problem is due to not implementing caching in proper way. I tried lot of stuff. But no luck..
import UIKit
class NewsTableViewController: UITableViewController {
var SLAFImages = [String]()
var SLAFHeading = [String]()
var SLAFText = [String]()
var SLAFCount = [Int]()
#IBOutlet weak var btnAction: UIBarButtonItem!
override func viewDidLoad() {
super.viewDidLoad()
let reposURL = NSURL(string: "https://www.helitours.lk/test.html")
// 2
do{
if let JSONData = NSData(contentsOfURL: reposURL!) {
// 3
if let json = try NSJSONSerialization.JSONObjectWithData(JSONData, options: NSJSONReadingOptions.MutableContainers) as? NSDictionary {
// 4
if let reposArray = json["items"] as? [NSDictionary] {
// 5
for item in reposArray {
if let name = item.valueForKey("title") {
SLAFHeading.append(name as! String)
}
if let Imgname = item.valueForKey("main_image") {
let urlimg=("http://airforce.lk/"+(Imgname as! String)) as String;
SLAFImages.append(urlimg)
}
}
}
}
}
}catch{}
let infoImage = UIImage(named: "crest png.png")
let imgWidth = infoImage?.size.width
let imgHeight = infoImage?.size.height
let button:UIButton = UIButton(frame: CGRect(x: 0,y: 0,width: imgWidth!, height: imgHeight!))
button.setBackgroundImage(infoImage, forState: .Normal)
//button.addTarget(self, action: Selector("openInfo"), forControlEvents: UIControlEvents.TouchUpInside)
SLAFCount=[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
SLAFText = ["While they like to munch on underwater plants, you might ",
"While they like to munch on underwater plants, you might ",
"While they like to munch on underwater plants, you might "]
//SLAFImages = ["Img1.jpg","Img2.jpg","Img3.jpg"]
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return SLAFHeading.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell =
self.tableView.dequeueReusableCellWithIdentifier(
"NewsTableCell", forIndexPath: indexPath)
as! NewsTableViewCell
let row = indexPath.row
cell.NewsHeading.font =
UIFont.preferredFontForTextStyle(UIFontTextStyleHeadline)
cell.NewsHeading.text = SLAFHeading[row]
if let url = NSURL(string: SLAFImages[row]) {
let task = NSURLSession.sharedSession().dataTaskWithURL(url) { (data, NSHTTPURLResponse, error) -> Void in
if error != nil {
print("thers an error in the log")
} else {
dispatch_async(dispatch_get_main_queue()) {
cell.NewsImage.image = UIImage(data: data!)
}
}
}
task.resume()
}
cell.NewsCount.text=String(SLAFCount[row])
cell.layoutIfNeeded()
return cell
}

Answer 1

Download image in Table view cell
Better way
this code will not increase more memory use of app.
//Initialize your catch variable
var cache = NSCache()
// MARK: - Private Image Download Block here
private func downloadPhoto(url: NSURL, completion: (url: NSURL, image: UIImage) -> Void) {
dispatch_async(downloadQueue, { () -> Void in
if let data = NSData(contentsOfURL: url) {
if let image = UIImage(data: data) {
dispatch_async(dispatch_get_main_queue(), { () -> Void in
cache.setObject(image, forKey: url)
completion(url: url, image: image)
})
}
}
})
}
//Call this Function from Table view
//Step 1
// Checking here Image inside Catch
let imageurl = NSURL(string:”Image URL here”)
let myimage = cache.objectForKey(imageurl!) as? UIImage
//Step 2
// Downloading here Promotion image
if myimage == nil {
downloadPhoto(imageurl!, completion: { (url, image) -> Void in
let indexPath_ = self.tblView.indexPathForCell(cell)
if indexPath.isEqual(indexPath_) {
cell.myImageView.image = image
}
})
}
I hope this will help you.