Question

I’m using pageControl in my application. View’s are not changing on click on dots but on the either end’s of pageControl, when i click view’s are changing. I want them to change on clicks on dot. What to do? Is there any method i need to implement?

Here’s the Code

#import "ScrollingViewController.h"

@implementation ScrollingViewController
@synthesize scrollView;
@synthesize pageControl;

- (void)viewDidLoad 
{
    [super viewDidLoad];
    [self setupPage];
    pageControl =[[UIPageControl alloc] initWithFrame:CGRectMake(0,390,320,100)]; 
    pageControl.userInteractionEnabled =YES;
    pageControl.numberOfPages = 5; 
    pageControl.currentPage = 0;
    [self.pageControl setBackgroundColor:[UIColor blackColor]];
    pageControl.enabled = TRUE;
    [pageControl setHighlighted:YES];
    [pageControl addTarget:self action:@selector(changePage:) forControlEvents:UIControlEventValueChanged];
    [self.view addSubview:pageControl]; 
}


- (void)didReceiveMemoryWarning 
{
    [super didReceiveMemoryWarning];
}

- (void)viewDidUnload 
{
    [scrollView release];
    [pageControl release];
}


- (void)dealloc 
{
    [super dealloc];
}


- (void)setupPage
{
    scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0,0,320,400)];
    [scrollView setContentSize:CGSizeMake(1000, 800)];
    //scrollView.contentSize = CGSizeMake(1000,800);
    scrollView.scrollsToTop = NO;
    [self.scrollView setBackgroundColor:[UIColor blackColor]];
    [scrollView setCanCancelContentTouches:NO];
    scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
    scrollView.clipsToBounds = YES;
    scrollView.scrollEnabled = YES;
    scrollView.pagingEnabled = YES;

    NSUInteger nimages = 0;
    CGFloat cx = 0;
    for (; ; nimages++) 
    {
        NSString *imageName = [NSString stringWithFormat:@"image%d.jpg", (nimages + 1)];
        UIImage *image = [UIImage imageNamed:imageName];
        if (image == nil) 
        {
            break;
        }
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

        CGRect rect = imageView.frame;
        rect.size.height = image.size.height;
        rect.size.width = image.size.width;
        rect.origin.x = ((scrollView.frame.size.width - image.size.width) / 2) + cx;
        rect.origin.y = ((scrollView.frame.size.height - image.size.height) / 2);

        imageView.frame = rect;

        [scrollView addSubview:imageView];
        [imageView release];

        cx += scrollView.frame.size.width;
    }

    self.pageControl.numberOfPages = nimages;
    [scrollView setContentSize:CGSizeMake(cx, [scrollView bounds].size.height)];
    scrollView.delegate = self;
    [self.view addSubview:scrollView];
}


- (void)scrollViewDidScroll:(UIScrollView *)_scrollView
{
    if (pageControlIsChangingPage) 
    {
        return;
    }


    CGFloat pageWidth = _scrollView.frame.size.width;
    int page = floor((_scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
    pageControl.currentPage = page;
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)_scrollView 
{
    pageControlIsChangingPage = NO;
}



- (IBAction)changePage:(id)sender 
{
    /*
     *  Change the scroll view
     */
    CGRect frame = scrollView.frame;
    frame.origin.x = frame.size.width * pageControl.currentPage;
    frame.origin.y = 0;
    [scrollView scrollRectToVisible:frame animated:YES];
    pageControlIsChangingPage = YES;
}

@end

Answer 1

Increase the width of the page control as much as possible. Even if you keep the width of page control short enough to as many dots that it cannot hold, it can show them. But fails to receive the action.