Checkbox selecting other checkboxes when one is selected - iphone

Question

I have created a custom class called Checkbox which changes its image on touch so that it gives a checkbox effect. However, when I click on one checkbox in the tableView, other checkboxes on seperate rows are selected too. Please could you tell me the problem with my code:
Checkbox.m
- (void)checkImages {
NSUInteger tag = [self tag];
BOOL val = [[NSUserDefaults standardUserDefaults] boolForKey:[NSString stringWithFormat:#"%i", tag]];
if (val == YES) {
[self setImage:[UIImage imageNamed:#"checkbox-pressed.png"] forState:UIControlStateNormal];
[[NSUserDefaults standardUserDefaults] setBool:NO forKey:[NSString stringWithFormat:#"%i", tag]];
}
else if (val == NO) {
[self setImage:[UIImage imageNamed:#"checkbox.png"] forState:UIControlStateNormal];
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:[NSString stringWithFormat:#"%i", tag]];
}
[[NSUserDefaults standardUserDefaults] synchronize];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
if ([[[[event allTouches] anyObject] view] tag] == [self tag]) {
[self checkImages];
}
}
RootViewController:
- (void)viewDidLoad
{
//This will set a solid background color
self.tableView.backgroundColor = [UIColor blackColor];
self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
if (_checkboxArray == nil) {
[self setItemArray:[[NSMutableArray alloc] init]];
}
if (_cellTextArray == nil) {
[self setCellTextArray:[[NSMutableArray alloc] init]];
}
if (![[NSUserDefaults standardUserDefaults] boolForKey:kFL]) {
NSMutableArray *custArr = [[NSMutableArray alloc] init];
for (int i = 0; i < [_checkboxArray count]; i ++) {
CheckBox *c = (CheckBox *)[_checkboxArray objectAtIndex:i];
[c setImage:[UIImage imageNamed:#"checkbox.png"] forState:UIControlStateNormal];
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:[NSString stringWithFormat:#"%i", [c tag]]];
[custArr addObject:c];
}
[_checkboxArray release];
[_checkboxArray setArray:custArr];
[custArr release];
[[NSUserDefaults standardUserDefaults] setBool:YES forKey:kFL];
[[NSUserDefaults standardUserDefaults] synchronize];
}
for (int i = 0; i < [textLabelArray count]; i++) {
NSDictionary *dict = [[NSDictionary alloc] initWithObjects:[NSArray arrayWithObjects:[textLabelArray objectAtIndex:i], [detailTextArray objectAtIndex:i], [cornLabelArray objectAtIndex:i], nil] forKeys:[NSArray arrayWithObjects:#"textLabel", #"detailTextLabel", #"cornerLabel", nil]];
[_cellTextArray addObject:dict];
[dict release];
}
for (int i = 0; i < [_cellTextArray count]; i++) {
CheckBox*btn = [[CheckBox alloc] init];
[btn setFrame:CGRectMake(0, 10, 40, 40)];
[btn setTag:i];
UIImage *img = [UIImage imageNamed:[[NSUserDefaults standardUserDefaults] boolForKey:[NSString stringWithFormat:#"%i", btn.tag]] ? #"checkbox.png":#"checkbox-pressed.png"];
[btn setImage:img forState:UIControlStateNormal];
[_checkboxArray addObject:btn];
[btn release];
}
[self.tableView reloadData];
[super viewDidLoad];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"CustomCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
CheckBox *btn;
UILabel *lab, *dlabl, *cornerLabel;
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
btn = (CheckBox *)[_checkboxArray objectAtIndex:indexPath.row];
[cell.contentView addSubview:btn];
//I added this code:
cell.textLabel.font = [UIFont fontWithName:#"Helvetica" size:12.0];
cell.textLabel.lineBreakMode = UILineBreakModeWordWrap;
cell.textLabel.numberOfLines = 3; // 0 means no max.
UIImageView* img = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"gradient7.png"]] autorelease];
[cell setBackgroundView:img];
lab = [[[UILabel alloc] initWithFrame:CGRectMake(40, 18, cell.contentView.frame.size.width-15, 22)] autorelease];
[lab setBackgroundColor:[UIColor clearColor]];
[lab setTextColor:[UIColor whiteColor]];
[lab setAdjustsFontSizeToFitWidth:YES];
[lab setTextAlignment:UITextAlignmentLeft];
[lab setTag:kTEXT_LABEL_TAG];
[cell.contentView addSubview:lab];
dlabl = [[[UILabel alloc] initWithFrame:CGRectMake(5, 54, cell.contentView.frame.size.width- 1, 22)] autorelease];
[dlabl setTextColor:[UIColor colorWithRed:1.0 green:0.80 blue:0.0 alpha:1.0]];
[dlabl setBackgroundColor:[UIColor clearColor]];
// [dlabl setAdjustsFontSizeToFitWidth:YES];
[dlabl setTextAlignment:UITextAlignmentLeft];
[dlabl setTag:kDETAIL_TEXT_LABEL_TAG];
[dlabl setFont:[UIFont systemFontOfSize:[lab font].pointSize - 3]];
[cell.contentView addSubview:dlabl];
cornerLabel = [[[UILabel alloc] initWithFrame:CGRectMake(cell.contentView.frame.size.width - 40, 19, 40, 20)] autorelease];
[cornerLabel setTextColor:[UIColor whiteColor]];
//[cornerLabel setFont:[UIFont systemFontOfSize:12]];
[cornerLabel setAdjustsFontSizeToFitWidth:YES];
[cornerLabel setBackgroundColor:[UIColor clearColor]];
[cornerLabel setTextAlignment:UITextAlignmentCenter];
[cornerLabel setTag:kCORNER_TEXT_LABEL_TAG];
[cell.contentView addSubview:cornerLabel];
[cornerLabel setAdjustsFontSizeToFitWidth:YES];
}
else {
lab = (UILabel *)[[cell contentView] viewWithTag:kTEXT_LABEL_TAG];
dlabl = (UILabel *)[[cell contentView] viewWithTag:kDETAIL_TEXT_LABEL_TAG];
cornerLabel = (UILabel *)[[cell contentView] viewWithTag:kCORNER_TEXT_LABEL_TAG];
btn = (CheckBox *)[[cell contentView] viewWithTag:kBTN_TAG];
}
NSDictionary *dict = [_cellTextArray objectAtIndex:indexPath.row];
lab.text = [dict objectForKey:#"textLabel"];
dlabl.text = [dict objectForKey:#"detailTextLabel"];
cornerLabel.text = [dict objectForKey:#"cornerLabel"];
if ([[NSUserDefaults standardUserDefaults] boolForKey:[NSString stringWithFormat:#"%d", indexPath.row]] == NO) {
[btn setImage:[UIImage imageNamed:#"checkbox-pressed.png"] forState:UIControlStateNormal];
}else {
[btn setImage:[UIImage imageNamed:#"checkbox.png"] forState:UIControlStateNormal];
}
return cell;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return 80.0f;
}

Answer 1

You are using tableView dequeueReusableCellWithIdentifier:CellIdentifier]. This is a good thing, but it means that in your table view, you have only as many cells as you can see. When you scroll and a cell leaves the screen on one end, it will then be reused and reenter the screen from the other end. And of course, the cell still contains the same checkbox, so if it was checked when it left the screen it still will be, if not, it won't.
Solving this should be pretty straight forward. In your tableView:(UITableView *)tableView cellForRowAtIndexPath: you already fill the cell accordingly to the item which should be displayed there (lab.text = [dict objectForKey:#"textLabel"]; and so on). So all you have to to is to save the checkboxes state for every item in your tableview and restore it there.
Hope that helps!