Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

How can I change the page on clicking the dots of UIPageControl

Here I have a pagecontrol which works good but on clicking on dot it doesn't change the page so please help in the function of changepage:

- (void)viewDidLoad {
    scrollView=[[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, 320, 420)];
    scrollView.delegate = self;
    [self.scrollView setBackgroundColor:[UIColor whiteColor]];
    [scrollView setCanCancelContentTouches:NO];
    scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
    scrollView.clipsToBounds = YES;
    scrollView.scrollEnabled = YES;
    [scrollView setShowsHorizontalScrollIndicator:NO];
    scrollView.pagingEnabled = YES;
    [self.view addSubview:scrollView];
    pageControl=[[UIPageControl alloc]initWithFrame:CGRectMake(0, 420, 320, 40)];
    [pageControl addTarget:self action:@selector(changepage:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:pageControl];
    
    UIView *blueView = [[UIView alloc] init];
    blueView.frame = CGRectMake(0, 0, 640, 480);
    blueView.backgroundColor = [UIColor whiteColor];
    [scrollView addSubview:blueView];
    self.pageControl.numberOfPages = 2;
    [scrollView setContentSize:CGSizeMake(640, 0)];
}

-(void)changepage:(id)sender
{
    int page = pageControl.currentPage;
    if (page < 0)
        return;
    if (page >= 2)
        return;
    CGRect frame = scrollView.frame;
    frame.origin.x = frame.size.width * page;
    frame.origin.y = 0;
    [scrollView scrollRectToVisible:frame animated:YES];
    
}

- (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;
}
like image 500
Vivek Sehrawat Avatar asked Dec 13 '12 06:12

Vivek Sehrawat


3 Answers

You can create one event change page:

- (IBAction)changePage:(id)sender {
    UIPageControl *pager=sender;
    int page = pager.currentPage;
    CGRect frame = imageGrid_scrollView.frame;
    frame.origin.x = frame.size.width * page;
    frame.origin.y = 0;
    [imageGrid_scrollView scrollRectToVisible:frame animated:YES];
}

Bind it to Pagecontrol's value changed event.

like image 64
Banker Mittal Avatar answered Nov 05 '22 13:11

Banker Mittal


This is very useful for pagecontrol dots click action change page index for swift 3 and swift 4 .

@IBAction func pageControlSelectionAction(_ sender: UIPageControl) {
    let page: Int? = sender.currentPage
    var frame: CGRect = self.yourcollectionview.frame
    frame.origin.x = frame.size.width * CGFloat(page ?? 0)
    frame.origin.y = 0
    self.yourcollectionview.scrollRectToVisible(frame, animated: true)
}
like image 13
Maulik Patel Avatar answered Nov 05 '22 12:11

Maulik Patel


Just to complete Banker Mittal's answer, the easiest way to do it in swift is to scroll the wanted rect to visible. You don't have to take care of "left" and "right" scrolling because iOS itself realizes which dot you tapped so you can just scroll to the correct frame:

private func moveScrollViewToCurrentPage() {

 //You can use your UICollectionView variable too instead of my scrollview variable
            self.scrollView
                .scrollRectToVisible(CGRect(
                    x: Int(self.scrollView.frame.size.width) * self.pager.currentPage,
                    y: 0,
                     width:Int(self.scrollView.frame.size.width),
                    height: Int(self.scrollView.frame.size.height)),
                                     animated: true)

    }
like image 5
Fry Avatar answered Nov 05 '22 13:11

Fry