iOS多图像分页和缩放问题

Question

有一些与这个问题相关的线程，但找不到可靠的解决方案。任何帮助，将不胜感激。如果你给它一个图像，这段代码很有用。放大完美。你给它两个图像滚动投影图像很好，但当你去放大它总是放大到第一个图像？不确定为什么viewForZoomingInScrollView方法无法确定您所在的视图。代码发布在下面

PagedScrollViewController.h

#import <UIKit/UIKit.h>
@interface PagedScrollViewController : UIViewController <UIScrollViewDelegate>
@property (nonatomic, strong) IBOutlet UIScrollView *scrollView;
@property (nonatomic, strong) IBOutlet UIPageControl *pageControl;
@property (nonatomic, strong) IBOutlet UIButton *cancelButtonClicked;
@property (nonatomic, strong) IBOutlet UILabel *headerTitle;
@property (nonatomic, strong) IBOutlet NSString *headerTitleS;
@property (nonatomic, strong) IBOutlet NSMutableArray *pageImages;
@property (nonatomic, strong) IBOutlet UITextView *caption;
@property (weak, nonatomic) IBOutlet UINavigationBar *navigationBar;
@property (nonatomic, strong) NSMutableArray *captionArray;

-(IBAction)cancelButtonClicked:(id)sender;

@end

PagedScrollViewController.m

@interface PagedScrollViewController ()
@property (nonatomic, strong) NSMutableArray *pageViews;

- (void)loadVisiblePages;
- (void)loadPage:(NSInteger)page;
- (void)purgePage:(NSInteger)page;
@end

@implementation PagedScrollViewController
@synthesize scrollView = _scrollView;
@synthesize pageControl = _pageControl;
@synthesize pageImages = _pageImages;
@synthesize pageViews = _pageViews;
@synthesize cancelButtonClicked = _cancelButtonClicked;
@synthesize headerTitle = _headerTitle;
@synthesize headerTitleS = _headerTitleS;
@synthesize caption = _caption;
@synthesize captionArray = _captionArray;

- (void)loadVisiblePages {
    // First, determine which page is currently visible
    CGFloat pageWidth = self.scrollView.frame.size.width;
    NSInteger page = (NSInteger)floor((self.scrollView.contentOffset.x * 2.0f + pageWidth) 
    / (pageWidth * 2.0f));

    // Update the page control
    self.pageControl.currentPage = page;

    NSObject *captionObject = [self.captionArray objectAtIndex:page];
    NSString *captionString = [NSString stringWithFormat:@"%@", [captionObject 
    valueForKey:@"caption"]]; 
    self.caption.text = captionString;

    // Work out which pages we want to load
    NSInteger firstPage = page - 1;
    NSInteger lastPage = page + 1;

    // Purge anything before the first page
    for (NSInteger i=0; i<firstPage; i++) {
        [self purgePage:i];
    }
        for (NSInteger i=firstPage; i<=lastPage; i++) {
        [self loadPage:i];
    }
    for (NSInteger i=lastPage+1; i<self.pageImages.count; i++) {
        [self purgePage:i];
    }
}

- (void)loadPage:(NSInteger)page {
    if (page < 0 || page >= self.pageImages.count) {
        // If it's outside the range of what we have to display, then do nothing
        return;
    }

    // Load an individual page, first seeing if we've already loaded it
    UIView *pageView = [self.pageViews objectAtIndex:page];
    if ((NSNull*)pageView == [NSNull null]) {
        CGRect frame = self.scrollView.bounds;
        frame.origin.x = frame.size.width * page;
        frame.origin.y = 0.0f;

        UIImageView *newPageView = [[UIImageView alloc] initWithImage:[self.pageImages 
        objectAtIndex:page]];

        newPageView.contentMode  = UIViewContentModeScaleAspectFit;
        newPageView.frame = CGRectMake((page*320), 0, 310, 320);
        self.scrollView.maximumZoomScale = 1.3;
        self.scrollView.contentSize = CGSizeMake(320*[self.pageImages count],389);
        self.scrollView.frame = CGRectMake(320*(self.pageControl.currentPage), 44, 310, 
        370);
        [self.scrollView addSubview:newPageView];
        [self.pageViews replaceObjectAtIndex:page withObject:newPageView];
    }
 }

- (void)purgePage:(NSInteger)page {
 if (page < 0 || page >= self.pageImages.count) {
    // If it's outside the range of what we have to display, then do nothing
    return;
}

// Remove a page from the scroll view and reset the container array
UIView *pageView = [self.pageViews objectAtIndex:page];
    if ((NSNull*)pageView != [NSNull null]) {
        [pageView removeFromSuperview];
        [self.pageViews replaceObjectAtIndex:page withObject:[NSNull null]];
     }
 }

-(UIView *) viewForZoomingInScrollView:(UIScrollView *)scrollView {
      self.scrollView.contentSize = CGSizeMake(320*[self.pageImages count],389);
     return [self.scrollView.subviews objectAtIndex:self.pageControl.currentPage];
}

- (void)viewDidLoad {
    [super viewDidLoad];
    self.scrollView.delegate = self;
    self.headerTitle.text = self.headerTitleS;
    // Set up the image we want to scroll & zoom and add it to the scroll view
    NSInteger pageCount = self.pageImages.count;

    // Set up the page control
    self.pageControl.currentPage = 0;
    self.pageControl.numberOfPages = pageCount;

    // Set up the array to hold the views for each page
    self.pageViews = [[NSMutableArray alloc] init];
    for (NSInteger i = 0; i < pageCount; ++i) {
    [self.pageViews addObject:[NSNull null]];
    }
}

- (void)viewWillAppear:(BOOL)animated {
   [super viewWillAppear:animated];
   // Load the initial set of pages that are on screen
   [self loadVisiblePages];
}

- (void)viewDidUnload {
   [super viewDidUnload];
   self.scrollView = nil;
   self.pageControl = nil;
   self.pageImages = nil;
   self.pageViews = nil;
}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
  [self loadVisiblePages];
}

-(IBAction)cancelButtonClicked:(id)sender{
   [self dismissViewControllerAnimated:YES completion:nil];
}

@end

Answer 1

这是我发现的工作。通过分页和缩放支持多个图像。享受！

#define VIEW_FOR_ZOOM_TAG (1)

@implementation SVViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    UIScrollView *mainScrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
    mainScrollView.pagingEnabled = YES;
    mainScrollView.showsHorizontalScrollIndicator = NO;
    mainScrollView.showsVerticalScrollIndicator = NO;

    CGRect innerScrollFrame = mainScrollView.bounds;

    for (NSInteger i = 0; i < 3; i++) {
    UIImageView *imageForZooming = [[UIImageView alloc] initWithImage:[UIImage imageNamed:  
    [NSString stringWithFormat:@"page%d", i + 1]]];
    imageForZooming.tag = VIEW_FOR_ZOOM_TAG;

    UIScrollView *pageScrollView = [[UIScrollView alloc] initWithFrame:innerScrollFrame];
    pageScrollView.minimumZoomScale = 1.0f;
    pageScrollView.maximumZoomScale = 2.0f;
    pageScrollView.zoomScale = 1.0f;
    pageScrollView.contentSize = imageForZooming.bounds.size;
    pageScrollView.delegate = self;
    pageScrollView.showsHorizontalScrollIndicator = NO;
    pageScrollView.showsVerticalScrollIndicator = NO;
    [pageScrollView addSubview:imageForZooming];

    [mainScrollView addSubview:pageScrollView];

    if (i < 2) {
        innerScrollFrame.origin.x += innerScrollFrame.size.width;
    }
    }

    mainScrollView.contentSize = CGSizeMake(innerScrollFrame.origin.x + 
    innerScrollFrame.size.width, mainScrollView.bounds.size.height);

    [self.view addSubview:mainScrollView];
   }

 - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
  return [scrollView viewWithTag:VIEW_FOR_ZOOM_TAG];
}

 - (NSUInteger)supportedInterfaceOrientations {
 return UIInterfaceOrientationMaskPortrait;
} 

- (BOOL)shouldAutorotate {
 return NO;
}

@end