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任何人都可以帮助我在分页滚动视图中嵌入可缩放滚动视图的示例代码,以便可以单独缩放和平移每个页面吗?

导航结构也类似于标签栏控制器 --> 带有按钮的导航控制器(按下按钮) --> 视图控制器,其中图像的水平滚动视图必须通过分页和缩放来实现。

这是我遵循的教程的链接:如何使用 UIScrollView 滚动和缩放内容

我实现的代码如下:

#import "ViewCorpBrochureController.h"

@interface ViewCorpBrochureController ()
@property (nonatomic, strong) NSArray *pageImages;
@property (nonatomic, strong) NSMutableArray *pageViews;

@property (nonatomic, strong) UIImageView *imageView;

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


- (void)centerScrollViewContents;
- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer;
- (void)scrollViewTwoFingerTapped:(UITapGestureRecognizer*)recognizer;



@end

@implementation ViewCorpBrochureController

@synthesize scrollView = _scrollView;
@synthesize pageControl = _pageControl;

@synthesize pageImages = _pageImages;
@synthesize pageViews = _pageViews;


@synthesize imageView = _imageview;



- (void)centerScrollViewContents {
    CGSize boundsSize = self.scrollView.bounds.size;
    CGRect contentsFrame = self.imageView.frame;

    if (contentsFrame.size.width < boundsSize.width) {
        contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2.0f;
    } else {
        contentsFrame.origin.x = 0.0f;
    }

    if (contentsFrame.size.height < boundsSize.height) {
        contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2.0f;
    } else {
        contentsFrame.origin.y = 0.0f;
    }

    self.imageView.frame = contentsFrame;
}

- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer {
    // Get the location within the image view where we tapped
    CGPoint pointInView = [recognizer locationInView:self.imageView];

// Get a zoom scale that's zoomed in slightly, capped at the maximum zoom scale specified       by the scroll view
    CGFloat newZoomScale = self.scrollView.zoomScale * 1.5f;
    newZoomScale = MIN(newZoomScale, self.scrollView.maximumZoomScale);

    // Figure out the rect we want to zoom to, then zoom to it
    CGSize scrollViewSize = self.scrollView.bounds.size;

    CGFloat w = scrollViewSize.width / newZoomScale;
    CGFloat h = scrollViewSize.height / newZoomScale;
    CGFloat x = pointInView.x - (w / 2.0f);
    CGFloat y = pointInView.y - (h / 2.0f);

    CGRect rectToZoomTo = CGRectMake(x, y, w, h);

    [self.scrollView zoomToRect:rectToZoomTo animated:YES];
}

- (void)scrollViewTwoFingerTapped:(UITapGestureRecognizer*)recognizer {
    // Zoom out slightly, capping at the minimum zoom scale specified by the scroll view
    CGFloat newZoomScale = self.scrollView.zoomScale / 1.5f;
    newZoomScale = MAX(newZoomScale, self.scrollView.minimumZoomScale);
    [self.scrollView setZoomScale:newZoomScale animated:YES];
}


#pragma mark -

- (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;

    // 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 = frame;
        [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]];
    }
}


#pragma mark -



- (void)viewDidLoad {
    [super viewDidLoad];




   self.title = @"CorporateBrochure";


    self.pageImages = [NSArray arrayWithObjects:
                       [UIImage imageNamed:@"CB1.jpg"],
                       [UIImage imageNamed:@"CB2.jpg"],
                       [UIImage imageNamed:@"CB3.jpg"],
                       [UIImage imageNamed:@"CB4.jpg"],
                       [UIImage imageNamed:@"CB5.jpg"],
                       [UIImage imageNamed:@"CB6.jpg"],
                       nil];

    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]];
    }


    /* If I use this the subview appears below the image
     UIImage *image = self.imageView.image;
    //UIImage *image = [UIImage imageNamed:@"CB2.jpg"];
    self.imageView = [[UIImageView alloc] initWithImage:image];
    self.imageView.frame = (CGRect){.origin=CGPointMake(0.0f, 0.0f), .size=image.size};
    [self.scrollView addSubview:self.imageView];
    self.scrollView.contentSize = image.size;
    */



    UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollViewDoubleTapped:)];
    doubleTapRecognizer.numberOfTapsRequired = 2;
    doubleTapRecognizer.numberOfTouchesRequired = 1;
    [self.scrollView addGestureRecognizer:doubleTapRecognizer];

    UITapGestureRecognizer *twoFingerTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollViewTwoFingerTapped:)];
    twoFingerTapRecognizer.numberOfTapsRequired = 1;
    twoFingerTapRecognizer.numberOfTouchesRequired = 2;
    [self.scrollView addGestureRecognizer:twoFingerTapRecognizer];


     }


- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    CGSize pagesScrollViewSize = self.scrollView.frame.size;
    self.scrollView.contentSize = CGSizeMake(pagesScrollViewSize.width * self.pageImages.count, pagesScrollViewSize.height);

    [self loadVisiblePages];

}


- (void)viewDidUnload {
    [super viewDidUnload];

    self.scrollView = nil;
    self.pageControl = nil;
    self.pageImages = nil;
    self.pageViews = nil;
}



- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {

    // Return the view that we want to zoom
    return self.imageView;
}




- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    return (interfaceOrientation == UIInterfaceOrientationMaskAll);
}



#pragma mark - UIScrollViewDelegate

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    // Load the pages which are now on screen
    [self loadVisiblePages];
}



- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
    // The scroll view has zoomed, so you need to re-center the contents
    [self centerScrollViewContents];
}

@end
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1 回答 1

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Ray Wenderlich 的教程有什么具体问题吗?

Apple 的文档中有一个非常好的示例,说明如何实现分页滚动视图,请参阅此处的 Photo Scroller 示例代码。我建议从那里开始。

从上面的链接:

“PhotoScroller”演示了使用嵌入式 UIScrollViews 和 CATiledLayer 来创建丰富的用户体验,用于显示和分页可以单独平移和缩放的照片。

注意:如果您的图像不是太大,您可以不使用CATiledLayer.

编辑 1:请参阅这个问题的回答,了解如何修改 Apple 的 Photo Scroller 代码以制作UIPageViewController您自己的视图控制器(而不是rootViewController)的子视图。

编辑 2:在 github 上查看这个示例项目。

于 2013-06-26T05:39:18.670 回答