Question

I have a table filled with tableviewcells that have an imageview as their highlight color.

Sometimes when I click on a cell, the imageview lags a bit to load. I was wondering how to reduce the lag?

I have the following:

cell.selectedBackgroundView = [DataSingleton sharedMySingleton].highlightView;

inside the method:

-(void) tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath{

Note: I am calling the singleton every time I click on it. I will try setting the image locally to see if that makes a difference.

EDIT: So I set the imageview locally in viewDidLoad, and it seems to react a lot faster. I guess my problem is the singleton, but I want to be able to change all the highlight images at once. Is there a way to have a global variable that will load fast?

Answer 1

I am not much sure but below may help in performance.

Instead of writing your code in willDisplayCell method. You can write in cellForRowIndexPath method.

something like this

static NSString *CellIdentifier = [NSString stringWithFormat:@"MyIdentifier%d",indexpath.row];

UITableViewCell *cell = [tv dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

 cell.selectedBackgroundView = [DataSingleton sharedMySingleton].highlightView;
}

The idea is set selectedbackgroundView only once when you allocate memory for that cell. You need to use reuseidentifier for this.

Hope this help.