Radio Button Issues - ios

Question

I am using onegray's Radio button class in one of my projects. the one mentioned here: Best radio-button implementation for IOS
I am using these radio buttons for my answer choices on a quiz. when the user clicks the next button, the labels are populated with new choices. the only problem is that the old ones dont disappear. So when I click next, the new set of buttons are placed on top of the old ones.
what is the simplest way to first check to see if they already exist.. and if so.. delete them.. before displaying the new ones?
here is my code.
#interface LABViewControllerQuiz ()
#end
#implementation LABViewControllerQuiz
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
int counter =0;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
_fileContents = [NSString stringWithContentsOfFile:[[NSBundle mainBundle]pathForResource:#"quizQuestions" ofType:#"txt"] encoding:NSUTF8StringEncoding error: nil];
_theScanner = [NSScanner scannerWithString:_fileContents];
_separator = [NSCharacterSet characterSetWithCharactersInString:#"~"];
_lineBreak =[NSCharacterSet characterSetWithCharactersInString:#"#"];
_alreadyGeneratedNumbers =[[NSMutableArray alloc]init];
_numQuestions =0;
_userAnswers = [[NSMutableArray alloc]init];
_answerKey = [[NSMutableArray alloc]init];
[self nextQuestion:nil];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
/*
#pragma mark - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
// Get the new view controller using [segue destinationViewController].
// Pass the selected object to the new view controller.
}
*/
- (IBAction)nextQuestion:(UIButton *)sender
{
_NextQuestionButton.enabled = YES;
_submitButton.enabled = NO;
NSLog(#"NumQuestion = %d", _numQuestions);
if (_numQuestions >9)
{
_NextQuestionButton.enabled = NO;
_submitButton.enabled = YES;
}else
{
int r = arc4random() %20;
while ([_alreadyGeneratedNumbers containsObject:[NSNumber numberWithInt:r]])
{
r = arc4random() %20;
}
[_alreadyGeneratedNumbers addObject:[NSNumber numberWithInt:r]];
while(![_theScanner isAtEnd])
{
NSLog(#"Location= %d", [_theScanner scanLocation]);
NSLog(#"Already Generated numbers:");
int i =0;
while (i < [_alreadyGeneratedNumbers count])
{
NSLog(#"%#", [_alreadyGeneratedNumbers objectAtIndex:i]);
i++;
}
NSString *line;
_lineArray = [[NSMutableArray alloc] init];
[_theScanner scanUpToCharactersFromSet:_lineBreak intoString:&line];
[_theScanner setCharactersToBeSkipped:_lineBreak];
NSScanner *inner = [NSScanner scannerWithString:line];
NSString *word;
int wordCount = 0;
NSLog(#"r = %d counter = %d", r, counter);
if (counter ==r)
{
while(![inner isAtEnd])
{
[inner scanUpToCharactersFromSet:_separator intoString:&word];
[inner setCharactersToBeSkipped:_separator];
[_lineArray insertObject:word atIndex:wordCount];
_questionText.text = [NSString stringWithFormat:#"Question %d \n %#", _numQuestions +1,[_lineArray objectAtIndex:0]];
wordCount++;
[_theScanner setScanLocation:0];
counter = 0;
}
[sender setHidden:YES];
NSMutableArray* buttons = [NSMutableArray arrayWithCapacity:4];
CGRect btnRect = CGRectMake(25, 420, 300, 30);
for (NSString* optionTitle in #[[_lineArray objectAtIndex:1], [_lineArray objectAtIndex:2], [_lineArray objectAtIndex:3], [_lineArray objectAtIndex:4]])
{
RadioButton* btn = [[RadioButton alloc] initWithFrame:btnRect];
[btn addTarget:self action:#selector(onRadioButtonValueChanged:) forControlEvents:UIControlEventValueChanged];
btnRect.origin.y += 40;
[btn setTitle:optionTitle forState:UIControlStateNormal];
[btn setTitleColor:[UIColor darkGrayColor] forState:UIControlStateNormal];
btn.titleLabel.font = [UIFont boldSystemFontOfSize:17];
[btn setImage:[UIImage imageNamed:#"unchecked.png"] forState:UIControlStateNormal];
[btn setImage:[UIImage imageNamed:#"checked.png"] forState:UIControlStateSelected];
btn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
btn.titleEdgeInsets = UIEdgeInsetsMake(0, 6, 0, 0);
[self.view addSubview:btn];
[buttons addObject:btn];
}
[buttons[0] setGroupButtons:buttons]; // Setting buttons into the group
[buttons[0] setSelected:NO]; // Making the first button initially selected
NSLog(#"the question is = %#", [_lineArray objectAtIndex:0]);
//NSLog(#"Line arrayINDEX %d = %#", wordCount,[_lineArray objectAtIndex:wordCount]); _numQuestions ++;
break;
}else
{
counter ++;
}
}
}
[_answerKey addObject:[_lineArray objectAtIndex:5]];
}
-(void) onRadioButtonValueChanged:(RadioButton*)sender
{
// Lets handle ValueChanged event only for selected button, and ignore for deselected
if(sender.selected)
{
NSLog(#"Selected: %#", sender.titleLabel.text);
}
}

Answer 1

Save buttons as an instance variable. You're already adding all your buttons into the array, you just throw the array out for some reason.
#interface LABViewControllerQuiz ()
#property (strong) NSMutableArray *buttons;
#end
And then this line:
NSMutableArray* buttons = [NSMutableArray arrayWithCapacity:4];
Becomes these lines:
if (self.buttons) {
[self.buttons makeObjectsPerformSelector:#selector(removeFromSuperview)];
[self.buttons removeAllObjects];
} else {
self.buttons = [NSMutableArray arrayWithCapacity:4];
}