Question

I have a custom cell which has two UILabel objects.

//AppEventCell.h
#import <UIKit/UIKit.h>

@interface AppEventCell : UITableViewCell
{
    UILabel * titleLabel;
    UILabel * periodLabel;
}
@property (nonatomic, retain) UILabel * titleLabel;
@property (nonatomic, retain) UILabel * periodLabel;
@end


//AppEventCell.m
#import "AppEventCell.h"

@implementation AppEventCell
@synthesize titleLabel, periodLabel;

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) {
        titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 13, 275, 15)];
        [self.contentView addSubview:titleLabel];

        periodLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 33, 275, 15)];
        [self.contentView addSubview:periodLabel];
    }
    return self;
}
@end


- (AppEventCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"NoticeTableCell";

    AppEventCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {

        cell = [[AppEventCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    [cell.titleLabel setText:((NSString *)[[listArray objectAtIndex:indexPath.row] valueForKey:KEY_TITLE])];

[cell.periodLabel setText:((NSString *)[[listArray objectAtIndex:indexPath.row] valueForKey:KEY_PERIOD])];

return cell;

}

Here’s a question. Where Should I release titleLabel and periodLabel? I think I should release them by myself. However, there is no dealloc() in AppEventCell(I created the method but it never called). I put the release in CellForRowAtIndexPath but error occured when cell reused.

Shouldn’t I release the objects?

Answer 1

1) Here you should release labels after adding them as subviews:

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) {
        titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 13, 275, 15)];
        [self.contentView addSubview:titleLabel];
        [titleLabel release];

        periodLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 33, 275, 15)];
        [self.contentView addSubview:periodLabel];
        [periodLabel release];
    }
    return self;
}

2) dealloc method should be called for your cells. It’s wrong that it is not called. Check if you are releasing your tableView and in - (AppEventCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
is another memory leak:

cell = [[[AppEventCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

Mark new cell as autoreleased object.

3) If cell is reused ([tableView dequeueReusableCellWithIdentifier:CellIdentifier];) then you should call release or autorelease.