在Iphone中使用页面控制扫描图像

Question

我正在尝试制作练习应用程序,我可以使用页面控制滚动图像.我能够滚动图像并能够包含页面控件.但我面临的问题是我无法将两者联系起来.这意味着当我滚动图像时,页面控件不受影响,当我更改页面控件时,图像的滚动不受影响.

我已经提到了这个:http://www.iosdevnotes.com/2011/03/uiscrollview-paging/用于滚动页面控件.

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

需要一些指导...谢谢..

Answer 1

检查是否已将滚动视图的委托设置给ViewController

并且您刚刚将 pageControlBeingUsed 设置为 YES 或 NO，并且尚未在 ViewController 中的任何位置使用它