iPhone - dequeueReusableCellWithIdentifier usage
- by Jukurrpa
Hi,
I'm working on a iPhone app which has a pretty large UITableView with data taken from the web, so I'm trying to optimize its creation and usage.
I found out that dequeueReusableCellWithIdentifier is pretty useful, but after seeing many source codes using this, I'm wondering if the usage I make of this function is the good one.
Here is what people usually do:
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:@"Cell"];
// Add elements to the cell
return cell;
And here is the way I did it:
NSString identifier = [NSString stringWithFormat:@"Cell @d", indexPath.row]: // The cell row
UITableViewCell* cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell != nil)
return cell;
cell = [[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:identifier];
// Add elements to the cell
return cell;
The difference is that people use the same identifier for every cell, so dequeuing one only avoids to alloc a new one.
For me, the point of queuing was to give each cell a unique identifier, so when the app asks for a cell it already displayed, neither allocation nor element adding have to be done.
In fine I don't know which is best, the "common" method ceils the table's memory usage to the exact number of cells it display, whislt the method I use seems to favor speed as it keeps all calculated cells, but can cause large memory consumption (unless there's an inner limit to the queue).
Am I wrong to use it this way? Or is it just up to the developper, depending on his needs?
