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@interface TableViewCellDemoViewController : UIViewController {

IBOutlet UITableView *tableView;

NSArray *dataSourceArray;

NSMutableDictionary *checkedDictionary;

}

- (void)checkButtonTapped:(id)sender forCellWithLabel:(NSString *)text;

@property (nonatomic, retain) IBOutlet UITableView *tableView;

@property (nonatomic, retain) NSArray *dataSourceArray;

@property (nonatomic, retain) NSMutableDictionary *checkedDictionary;

@end

Inside the .m file I need to properly create the cells…

- (UITableViewCell *)tableView:(UITableView *)_tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
	BaseCell *cell = (BaseCell *)[_tableView dequeueReusableCellWithIdentifier:@"BaseCell"];

	if (!cell) {
		cell = [[[NSBundle mainBundle] loadNibNamed:@"BaseCell" owner:self options:nil] lastObject];
	}

	cell.selectionStyle = UITableViewCellSelectionStyleNone;

	cell.cellLabel.backgroundColor = [UIColor clearColor];
	cell.cellLabel.font = [UIFont fontWithName:@"Helvetica" size:17];

	cell.cellLabel.text = [dataSourceArray objectAtIndex:indexPath.row];
	cell.parentViewController = self;

    //let's use the cellLabel.text as key inside our checkedDictionary. IMPORTANT: This only works, if information inside cellLabel.text is unique for every row. If you have the same text twice in your datasourceArray, this will cause to some unexpected behavior.

    NSString *key = cell.cellLabel.text;

    BOOL checked = [[checkedDictionary objectForKey:key]boolValue];

    [cell.checkButton setBackgroundImage:(checked) ? [UIImage imageNamed:@"checked.png"] : [UIImage imageNamed:@"unchecked.png"] forState:UIControlStateNormal];

	return (UITableViewCell *)cell;
}

…and add a method, that will get called, if I tap on the check / uncheck button

- (void)checkButtonTapped:(id)sender forCellWithLabel:(NSString *)text {
    UIButton *button = (UIButton  *)sender;

    //like above, we're using the information inside the label (text) as unique identifier = key
    NSString *key = text;

    BOOL checked = [[checkedDictionary objectForKey:key]boolValue];

    //depending on whether the row has been checked before or not, we write YES / NO to our checkedDictionary
    if (checked) {
       [checkedDictionary setValue:@"NO" forKey:text];
        checked = NO;
    }
    else {
        [checkedDictionary setValue:@"YES" forKey:text];
        checked = YES;
    }

    //finally set the new button background image
    [button setBackgroundImage:(checked) ? [UIImage imageNamed:@"checked.png"] : [UIImage imageNamed:@"unchecked.png"] forState:UIControlStateNormal];
}

Finally, I create an empty user interface for Interface Builder and add a UITableViewCell object to it. I also create a new class, named “BaseCell” and set it as custom class for my UITableViewCell.
After adding a UILabel and UIButton object to my cell, I properly link everything and my BaseCell.h file will look like this:

#import <UIKit/UIKit.h>

@interface BaseCell : UITableViewCell {

    IBOutlet UILabel *cellLabel;
    IBOutlet UIButton *checkButton;
    UIViewController *parentViewController;
}

- (IBAction)checkButtonAction:(id)sender;

@property (assign) IBOutlet UILabel *cellLabel;
@property (assign) IBOutlet UIButton *checkButton;
@property (assign) UIViewController *parentViewController;
@end

Last but not least, the .m file will make a call to “checkButtonTapped” method inside my UITableViewController’s class like this:

- (IBAction)checkButtonAction:(id)sender {
    if (self.parentViewController) { //call method inside TableViewCellDemoViewController and submit the sender object (= button) and the text inside the label. We will use the text as unique identifier (=key) inside our checkedDictionary (also part of TableViewCellDemoViewController class)
        [self.parentViewController performSelector:@selector(checkButtonTapped: forCellWithLabel:) withObject:sender withObject:[self.cellLabel text]];
    }
}

If we break down the steps, our app will basically perform the following tasks:

1. Set up custom UITableView cells, containing a UILabel and UIButton

2. If user taps on the button, make a call from BaseCell class to TableViewCellDemoViewController class and submit both the sender button and text inside the UILabel

3. Use the UILabel text to look up a matching key inside our “checkedDictionary” object

4. Change background image of the UIButton, depending on whether (3) exists and whether it is YES or NO.