使用 Alamofire 加载图像非常慢

Question

I am fetching JSON data from my website to a table view with image view. Data is loading fast except the images are very slow in loading and makes the tableview not responding.

Here is my cellForRowAt code:

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let customCell = tableView.dequeueReusableCell(withIdentifier: TableViewCell.identifier, for: indexPath) as! TableViewCell
    //let cell = tableView.dequeueReusableCell(withIdentifier: "myCell", for: indexPath)
    let item = data[indexPath.row]
    customCell.AdTitle?.text = item["title"].string
    customCell.AdDate?.text = item["time"].string
    
    if let imageUrl = item["document"].string {
        AF.request("https://mysite.co/uploads/" + imageUrl).responseImage { response in
            if case .success( _) = response.result {
                let url = NSURL(string:("https://mysite.co/uploads/" + imageUrl))
                let imagedata = NSData.init(contentsOf: url! as URL)
                
                if imagedata != nil {
                    customCell.AdImage.image = UIImage(data:imagedata! as Data)
                }
            }
        }
    }
    
    return customCell
}

Answer 1

You can simply load your images with advance cache system through SDWebImage like below:

let imageURL = URL(string: "youRemoteImageURL") //Image URL     
yourImageView.sd_setImage(with: imageURL, placeholderImage: UIImage(named: "placeholder.png"))

Your tableViewCell will look like below:

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
   let customCell = tableView.dequeueReusableCell(withIdentifier: TableViewCell.identifier, for: indexPath) as! TableViewCell

   let item = data[indexPath.row]
   customCell.AdTitle?.text = item["title"].string
   customCell.AdDate?.text = item["time"].string
   
   let imageUrl = item["document"].string
   let url = NSURL(string:("https://mysite.co/uploads/" + imageUrl))
   customCell.AdImage.sd_setImage(with: url, placeholderImage: UIImage(named: "placeholder.png"))

   return customCell
}

Answer 2

Your code is fine. You have to load the image in main thread. The edited code is given below. Please try it and let me know

 func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let customCell = tableView.dequeueReusableCell(withIdentifier: TableViewCell.identifier, for: indexPath) as! TableViewCell
    //let cell = tableView.dequeueReusableCell(withIdentifier: "myCell", for: indexPath)
    let item = data[indexPath.row]
    customCell.AdTitle?.text = item["title"].string
    customCell.AdDate?.text = item["time"].string
    
    if let imageUrl = item["document"].string {
        AF.request("https://mysite.co/uploads/" + imageUrl).responseImage { response in
            if case .success( _) = response.result {
                let url = NSURL(string:("https://mysite.co/uploads/" + imageUrl))
                let imagedata = NSData.init(contentsOf: url! as URL)
                
                if imagedata != nil {
                    DispatchQueue.main.async {
                        customCell.AdImage.image = UIImage(data:imagedata! as Data)
                    }
                   
                }
            }
        }
    }
    
    return customCell
}