CODEWITHSUNDEEP
objective-cioscocoa-touchuitableview
user1051935
user1051935

Reputation: 589

Memory limit to number of items in table view

Is there a memory issue regarding the number of items in the list I am displaying in my table view? If the user keeps adding items will the application eventually crash or something due to memory issues?

Upvotes: 1

Views: 317

Answers (2)

Sid
Sid

Reputation: 9536

To answer your questions:

  1. There's no black and white answer to this. To try my best to explain, think of UITableView as sort of like a visual data array. In fact, most people (myself included) use a source data object like an NSArray or an NSDictionary to provide the display data for a UITableView. All the memory limitations that would apply to these objects (arrays and dictionaries) apply to your UITableView, assuming your UITableView is set up properly and you're using the recommended techniques for reusing cells. What this boils down to is: Is it possible to have a very large UITableView? - Yes. How long though, this I don't know. I've created UITableViews with complex subclassed cells and 200 rows and they worked fine. It depends on how you set up the table and the data source you're using. Bear in mind again that the limitation is due to the data source. Have an extremely large array and eventually your device will throw a memory warning. As a best practice, use pagination. There are tonnes of tutorials online to enable paging on UITableViews. Lazy load your images (if any) if they are being downloaded.

  2. Yes you can. You can do lots of amazing things if you're creative enough while subclassing UITableViewCells. Otherwise, you can use the standard UITableViewCell as well. There are two labels on there: The textLabel and the detailTextLabel. Use these two to display the data you want.

  3. Your UITableViewDelegate has a didSelectRowAtIndexPath method which you can implement. As long as your view controller housing the UITableView is set to be it's delegate, it will respond to didSelectRowAtIndexPath.

  4. Just empty the array you're using as a data source (bear in mind that your numberOfRowsInSection data source method MUST use the array count) and call reloadData on the UITableView

EDIT: The question got edited, so only point 1 from the above 4 points applies to the question :) The others are nice to know though

Upvotes: 1

David Dunham
David Dunham

Reputation: 8329

Nothing table-specific, but yes, you will run out.

The most important thing is probably to use dequeueReusableCellWithIdentifier: in your tableView:cellForRowAtIndexPath: delegate method. This basically cuts down memory usage to the number of visible cells (plus one being scrolled into view).

Upvotes: 0

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