CODEWITHSUNDEEP
iosuitableviewswiftasynchronous
Orkhan Alizade
Orkhan Alizade

Reputation: 7549

How to async load images on dynamic UITableView?

Now I have a custom cell with the image and label. Later I print these cells by:

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cell:customCell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! customCell

    var url = NSURL(string: postCover[indexPath.row])

    if let data = NSData(contentsOfURL: url!) { 
        cell.cellImage.image = UIImage(data: data)
    }

    var title = postTitle[indexPath.row]

    cell.cellLabel.text = title

    let indexPath = tableView.indexPathForSelectedRow()

    return cell
}

and when I open an app and scroll it freezes. How can I fix this bug?

I read about it, that I must use async image loading in my tableView, but don't I load them async already?

I searched and think about it 4-5 days and nothing. Can anyone give me some tips, please?

Upvotes: 0

Views: 11370

Answers (3)

Mukesh
Mukesh

Reputation: 3690

create a bridging header in swift.Import AFNetworking header files

and then find these method setImageWithURLRequest

cell.imageView.setImageWithURLRequest you can call in these way

Upvotes: -1

BourneWeng
BourneWeng

Reputation: 21

You can use third part Library SDWebImage on gitHub . It`s base on Objective-C, and there is another Library Kingfisher which base on Swift. And maybe this is what you want.

Upvotes: 2

Sanjay Mohnani
Sanjay Mohnani

Reputation: 5967

You can schedule the downloading of image asynchronously for each cell using GCD as- 

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cell:customCell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! customCell

    var url = NSURL(string: postCover[indexPath.row])

cell.imageView.image = nil;
        dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
        dispatch_async(queue, ^(void) {

            NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:parsedData[@"imageLR"]];

            UIImage* image = [[UIImage alloc] initWithData:imageData];
            if (image) {
                 dispatch_async(dispatch_get_main_queue(), ^{
                     if (cell.tag == indexPath.row) {
                         cell.imageView.image = image;
                         [cell setNeedsLayout];
                     }
                 });
             }
        });

return cell
}

for Swift you can do so as

if let data = self.cache.objectForKey(urlString) as? NSData {
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)) {
            let image = UIImage(data: data)
            dispatch_async(dispatch_get_main_queue()) {
                cell.imageView.image = image;
            }
        }

Upvotes: 2

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