How to call image urls and image view in cell for index path function for a collection view

Question

I want to asynchronously dispatch 8 image urls in a collection view. I have created a class for collection view cell and also made an outlet to imageview in it. Now I want to configure the imageview from main view controller. Here is the code

    let reuseIdentifier = "PhotosCollectionViewCell" // also enter this string as the cell identifier in the storyboard
   var items = ["1", "2", "3", "4", "5", "6", "7", "8"]

    // tell the collection view how many cells to make
    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
       return self.items.count

    }

    // make a cell for each cell index path
    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

        // get a reference to our storyboard cell
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! PhotosCollectionViewCell


        cell.imageView = imageView

        return cell



    }

    func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
        // handle tap events
        print("You selected cell #\(indexPath.item)!")
    }



    func loadImage() {
        dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0)) {
            let urlString = "http://charcoaldesign.co.uk/AsyncImageView/Forest/IMG_0352.JPG"
            let url = NSURL(string: urlString)
            let data = NSData(contentsOfURL: url!)
            dispatch_async(dispatch_get_main_queue(), {
             self.imageView.image = UIImage(data: data!)
//              self.items[0] = (data as? String)!

            })

        }
    }
}

use UIImageView+WebCache for async image in collection view – Prashant Tukadiya Aug 22 '16 at 12:09 — Prashant Tukadiya, Aug 22 '16 at 12:09

good4pc · Answer 1 · 2016-08-23T05:11:01.827

0

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {

    // get a reference to our storyboard cell
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! PhotosCollectionViewCell


    cell.imageView = imageView
    loadImage(imageView, urlPAssed: urlString)
    return cell
}
     func loadImage(imageViewObj : UIImageView , urlPAssed : NSString) {

    //let urlString = "http://charcoaldesign.co.uk/AsyncImageView/Forest/IMG_0352.JPG"
    let url = NSURL(string: urlPAssed as String)
    NSURLSession.sharedSession().dataTaskWithURL(url!) { (data, response, error) in
        if(error==nil)
        {
            dispatch_async(dispatch_get_main_queue(), { () -> Void in
                imageViewObj.image = UIImage(data: data!)

            })
        }
        else
        {
            imageViewObj.image = UIImage(named: "dummy")
        }
        }.resume()
     }

edited Aug 23 '16 at 05:11

answered Aug 22 '16 at 12:01

good4pc

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4
17

Thank you for the reply .here i am having 8 image urls how can i run a loop,so that i can display 8 images in a collection view-good4pc – Venky Aug 22 '16 at 12:05
pass your imageurl along with the imageView like this, so it will be called dynamically according to your collectionViewCell. loadImage(imageView, url) , func loadImage(imageViewObj : UIImageView , url : NSString) – good4pc Aug 22 '16 at 12:18
I am getting lot of errors please give me a detailed solution – Venky Aug 22 '16 at 12:43

score 0 · Answer 2 · edited May 23 '17 at 12:15

Here is a extension to make things more easy.

extension UIImageView {
    func downloadImageFrom(link link:String, contentMode: UIViewContentMode) {
        NSURLSession.sharedSession().dataTaskWithURL( NSURL(string:link)!, completionHandler: {
            (data, response, error) -> Void in
            dispatch_async(dispatch_get_main_queue()) {
                self.contentMode =  contentMode
                if let data = data { self.image = UIImage(data: data) }
            }
        }).resume()
    }
}

cell.imageView.downloadImageFrom(link: imageLinkArray[indexPath.row], contentMode: UIViewContentMode.ScaleAspectFit)  //set your image from link array.

Also you can look below url for more help.
how to implement lazy loading of images in table view using swift

How to call image urls and image view in cell for index path function for a collection view

2 Answers2