CODEWITHSUNDEEP
iosxcodeasynchronousuitableviewnsurlconnection
user984694
user984694

Reputation:

NSURLConnection delay leads to an empty UItableViewCell without the picture

My app downloads the user's Facebook profile picture with an asynchronous (NSURLConnection) connection so that it can display the profile picture on a customized UITableViewCell. The problem is; the customized tableViewCell is created before the picture gets downloaded so the delay leads to an empty tableViewCell without the picture. How can I solve this problem?

My approach is to reach each cell by using a (for-in enumeration) and (a tag for each cell) in "connectionDidFinishLoading" method.

So guys, what do you think about my approach and do you have any better approaches???

Thanks for your help, E.

Upvotes: 0

Views: 136

Answers (1)

Patrick Goley
Patrick Goley

Reputation: 5417

Trying to tag and loop through your cells to find matches won't work because of UITableViewCell reuse. There are only as many cells in memory as you can see on screen, and these cells get recycled to display different data. Therefore, you won't be able to create a tag for each row in your table view, because the table view is only using a handful of cells.

What you should do instead is create a UITableViewCell subclass that knows how to asynchronously download and display in the image itself. Using the UIImageView category from AFNetworking is perfect for doing something like this, instead of having to manage the URL connection yourself. Import this category in your cell subclass, and write a method that calls setImageWithURL: to asynchronously download and display the image. Also, make sure to overload the UITableViewCell method prepareForReuse, in which you should call cancelImageRequestOperation on your image view. This is so the request to download the image is cancelled if the cell is reused before the download is complete.

Upvotes: 1

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