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POHow can I speed up a UITableView?
 

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  1. POHow can I speed up a UITableView?
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    <p>I have a UITableView with about 400 cells in 200 sections and it's a little sluggish in responding to user interaction (scrolling, selecting cells.) I've made sure the methods for retrieving cells and header views do the bare minimum as it's running, and I don't think I'm doing anything out of the ordinary to make it slow. The cells and headers just have a background image and text. Has anyone else had this kind of problem, and do you know any way to make it run a little faster?</p> <p><strong>Edit:</strong> I'm offering a bounty because I'd love to get some useful feedback on this. I <em>don't</em> think the answer lies in a problem in my code. Instead I'm looking for strategies to re-engineer the UITableView so that it runs faster. I'm totally open to adding new code and I look forward to hearing what you guys have to say.</p> <p>Sluggishness is observed on both the simulator and my device, an iPhone 4. Here are my implementations of <code>viewForHeaderInSection</code> and <code>cellForRowAtIndexPath</code>, which are the only <code>UITableViewDelegate</code> methods implemented nontrivially. I am reusing cells and header views.</p> <pre><code>- (UIView*)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger) section { HaikuHeaderView* view= [m_sectionViews objectAtIndex:section]; NSMutableArray* array= [m_haikuSearch objectAtIndex:section]; Haiku* haiku= [array objectAtIndex:0]; [view.poetLabel setText:[haiku nameForDisplay]]; return view; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease]; cell.backgroundView= [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"cell gradient2.png"]]; // (Set up a bunch of label attributes in the cell...) } NSMutableArray* array= [m_haikuSearch objectAtIndex:indexPath.section]; Haiku* haiku = [array objectAtIndex:indexPath.row]; cell.textLabel.text = [haiku.m_lines objectAtIndex:0]; return cell; } </code></pre>
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    1. COit would be helpful if you can show us how you have implemented those methods. Not the whole code but just the basic logic
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    2. COWhat devices are you testing on? Or is the sluggishness also observed on your Mac?
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    3. COPossible duplicate that answers your question: [Tricks for improving iPhone UITableView scrolling performance?](http://stackoverflow.com/questions/1352479/tricks-for-improving-iphone-uitableview-scrolling-performance)
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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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