Swiping Images with Page Control in Iphone - iphone

Question

I am trying to make practice app where i can scroll images with page control. I am able to scroll images and able to include the page control. But the problem i face is i am not able to interlink the two. Meaning to say when I scroll the images, the page control is not affected and when i change the page control, the scrolling of the images is unaffected.
I have referred to this: http://www.iosdevnotes.com/2011/03/uiscrollview-paging/ for the scrolling with page control.
Viewcontroller.h
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController <UIScrollViewDelegate>{
UIScrollView *scrollView;
UIPageControl *pageControl;
BOOL pageControlBeingUsed;
}
#property (nonatomic, retain) IBOutlet UIScrollView *scrollView;
#property (nonatomic, retain) IBOutlet UIPageControl *pageControl;
- (IBAction)changePage;
#end
Viewcontroller.m
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize scrollView,pageControl;
- (void)scrollViewDidScroll:(UIScrollView *)sender {
if (!pageControlBeingUsed) {
// Switch the indicator when more than 50% of the previous/next page is visible
CGFloat pageWidth = self.scrollView.frame.size.width;
int page = floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
self.pageControl.currentPage = page;
}
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
pageControlBeingUsed = NO;
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
pageControlBeingUsed = NO;
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSArray *images = [[NSArray alloc] initWithObjects:[UIImage imageNamed:#"1.jpeg"],[UIImage imageNamed:#"2.jpeg"],[UIImage imageNamed:#"3.jpeg" ], nil];
self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * images.count, self.scrollView.frame.size.height);
for (int i = 0; i < images.count; i++) {
CGRect frame;
frame.origin.x = self.scrollView.frame.size.width * i;
frame.origin.y = 0;
frame.size = self.scrollView.frame.size;
UIImageView* imgView = [[UIImageView alloc] init];
imgView.image = [images objectAtIndex:i];
imgView.frame = frame;
[scrollView addSubview:imgView];
}
self.pageControl.currentPage = 0;
self.pageControl.numberOfPages = images.count;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
self.scrollView = nil;
self.pageControl = nil;
}
- (IBAction)changePage{
// update the scroll view to the appropriate page
CGRect frame;
frame.origin.x = self.scrollView.frame.size.width * self.pageControl.currentPage;
frame.origin.y = 0;
frame.size = self.scrollView.frame.size;
[self.scrollView scrollRectToVisible:frame animated:YES];
pageControlBeingUsed = YES;
}
#end
Need some guidance on this... Thanks..

Answer 1

I learned page control and scrollView from this tutorial, its very clearly written, hope it helps you http://www.raywenderlich.com/10518/how-to-use-uiscrollview-to-scroll-and-zoom-content

Answer 2

Check whether you have set the delegate of the scroll view to the ViewController
And you have just set the pageControlBeingUsed to YES or NO and you have not used it anywhere in the ViewController