我想在滚动滑块后将图像缩小到原始尺寸。 我使用 REPagedScrollView 库来实现滑块。 我在滑块中有5张图片。现在放大第一张图像，然后立即滚动滑块以查看第二张图像。然后返回查看第1张图片。第一张图像没有缩小。该图像仍处于放大模式。 我怎么能解决这个问题。
提前致谢。
我正在使用以下代码。
-(void)slideShow
{
[scrollView removeFromSuperview];
scrollView = [[REPagedScrollView alloc] initWithFrame:self.scrollVw.bounds];
scrollView.delegate=self;
scrollView.pageControl.pageIndicatorTintColor=[UIColor clearColor];
scrollView.pageControl.currentPageIndicatorTintColor=[UIColor clearColor];
current_page=0;
for(int i=0;i<[self.PhotoImgArr count];i++){
// Image view
image_scroll = [[UIScrollView alloc] initWithFrame:CGRectMake(0,0,self.scrollVw.frame.size.width,self.scrollVw.frame.size.height)];
self.image_view = [[AsyncImageView alloc] initWithFrame:CGRectMake(0,0, image_scroll.frame.size.width, image_scroll.frame.size.height)];
self.image_view.backgroundColor=[UIColor clearColor];
// self.image_view.contentMode = UIViewContentModeScaleAspectFit;
self.image_view.clipsToBounds = true;
self.image_view.userInteractionEnabled = YES;
//self.image_view.image=[UIImage imageNamed:@"Stars"];
self.image_view.imageURL =[NSURL URLWithString:[self.PhotoImgArr objectAtIndex:i]];
doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTap:)];
[doubleTap setNumberOfTapsRequired:2];
[self.image_view addGestureRecognizer:doubleTap];
// twoFingerPinch = [[UIPinchGestureRecognizer alloc]
// initWithTarget:self
// action:@selector(twoFingerPinch:)];
// [self.image_view addGestureRecognizer:twoFingerPinch];
[image_scroll setDelegate:self];
[image_scroll setShowsHorizontalScrollIndicator:NO];
[image_scroll setShowsVerticalScrollIndicator:NO];
image_scroll.tag=i+1;
// image_scroll.backgroundColor=[UIColor purpleColor];
image_scroll.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
self.image_view.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
image_scroll.contentSize = CGSizeMake(self.image_view.bounds.size.width-500, self.image_view.bounds.size.height-300);
image_scroll.decelerationRate = UIScrollViewDecelerationRateFast;
[image_scroll setMaximumZoomScale:4.0];
// image_scroll.minimumZoomScale = 1.0;
[image_scroll setZoomScale:[image_scroll minimumZoomScale]];
//image_scroll.zoomScale = 1.0;
[image_scroll addSubview:self.image_view];
[scrollView addPage:image_scroll];
}
scrollView.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
scrollView.tag=0;
[self.scrollVw addSubview:scrollView];
[scrollView scrollToPageWithIndex:self.selected_index animated:YES];
}
- (void)twoFingerPinch:(UIPinchGestureRecognizer *)recognizer
{
NSLog(@"twoFingerPinch");
float newScale = [image_scroll zoomScale] / 2.0;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[recognizer locationInView:recognizer.view]];
[image_scroll zoomToRect:zoomRect animated:YES];
}
- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer {
// zoom in
NSLog(@"handleDoubleTap");
UIScrollView *imageScroll = (UIScrollView *)[self.view viewWithTag:self.selected_index+1];
float newScale = [imageScroll zoomScale] * 2.0;
if (newScale > imageScroll.maximumZoomScale){
newScale = imageScroll.minimumZoomScale;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
[imageScroll zoomToRect:zoomRect animated:YES];
}
else{
newScale = imageScroll.maximumZoomScale;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
[imageScroll zoomToRect:zoomRect animated:YES];
}
}
#pragma mark Utility methods
- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center {
CGRect zoomRect;
// the zoom rect is in the content view's coordinates.
// At a zoom scale of 1.0, it would be the size of the imageScrollView's bounds.
// As the zoom scale decreases, so more content is visible, the size of the rect grows.
zoomRect.size.height = [image_scroll frame].size.height / scale;
zoomRect.size.width = [image_scroll frame].size.width / scale;
// choose an origin so as to get the right center.
zoomRect.origin.x = center.x - (zoomRect.size.width / 2.0);
zoomRect.origin.y = center.y - (zoomRect.size.height / 2.0);
return zoomRect;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView1
{
UIScrollView *imageScroll = (UIScrollView *)[self.view viewWithTag:self.selected_index+1];
if(scrollView1.tag ==0){
CGFloat pageWidth = scrollView1.frame.size.width;
current_page = floor((scrollView1.contentOffset.x - pageWidth / 2.0) / pageWidth) + 1;
self.selected_index=current_page;
self.lblHeader.text=[NSString stringWithFormat:@"%ld of %lu",self.selected_index+1,(unsigned long)[self.PhotoImgArr count]];
}
else
{
CGFloat offsetX = (imageScroll.bounds.size.width > imageScroll.contentSize.width)?
(imageScroll.bounds.size.width - imageScroll.contentSize.width) * 0.5 : 0.0;
CGFloat offsetY = (imageScroll.bounds.size.height > imageScroll.contentSize.height)?
(imageScroll.bounds.size.height - imageScroll.contentSize.height) * 0.5 : 0.0;
[scrollView1.subviews objectAtIndex:0].center = CGPointMake(imageScroll.contentSize.width * 0.5 + offsetX,imageScroll.contentSize.height * 0.5 + offsetY);
}
}
-(UIView *) viewForZoomingInScrollView:(UIScrollView *)scrollView1
{
if([scrollView1.subviews count]>0){
return [scrollView1.subviews objectAtIndex:0];
}
return nil;
}
答案 0 :(得分：2)
确定首先，不要使用REPagedScrollView而是可以通过更改视图的x位置将页面设置为scrollview，如果你的话，它对你的zooming很有用使用REPagedScrollView有一些复杂情况，你无法将子视图作为scrollview，而是你得到一个UIView实例
最好使用普通UIScrollView这对你的情况有好处，并且在UIPageControl中设置REPagedScrollView，就像在视图控制器视图中一样。
首先设置如下页面
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
_scrollPager = [[UIScrollView alloc] initWithFrame:self.view.bounds];
_scrollPager.delegate=self;
_scrollPager.pagingEnabled = YES;
_current_page=0;
_prev_next_index = 0;
_PhotoImgArr = [[NSMutableArray alloc] initWithObjects:@"00.jpg",@"01.jpg",@"02.jpg",@"03.jpg", nil];
CGSize totalContentSize = CGSizeMake(self.view.bounds.size.width [_PhotoImgArr count], self.view.bounds.size.height);
_scrollPager.contentSize = totalContentSize;
[self.view addSubview:_scrollPager];
[self setUpPager];
}
- (void)setUpPager
{
for(int i=0;i<[self.PhotoImgArr count];i++)
{
// Image view
UIScrollView *image_scroll = [[UIScrollView alloc] initWithFrame:CGRectMake(i * self.view.bounds.size.width, 0, self.view.bounds.size.width, self.view.bounds.size.height)];
UIImageView *image_view = [[UIImageView alloc] initWithFrame:image_scroll.bounds];
image_view.backgroundColor=[UIColor clearColor];
image_view.clipsToBounds = true;
image_view.image = [UIImage imageNamed:_PhotoImgArr[i]];
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTap:)];
[doubleTap setNumberOfTapsRequired:2];
[image_scroll setDelegate:self];
[image_scroll setShowsHorizontalScrollIndicator:NO];
[image_scroll setShowsVerticalScrollIndicator:NO];
image_scroll.tag=i;
image_scroll.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
image_view.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
image_scroll.contentSize = image_scroll.bounds.size;
image_scroll.decelerationRate = UIScrollViewDecelerationRateFast;
image_scroll.minimumZoomScale = 1.0f;
image_scroll.maximumZoomScale = 3.0f;
[image_scroll addSubview:image_view];
[image_scroll addGestureRecognizer:doubleTap];
[_scrollPager addSubview:image_scroll];
}
_scrollPager.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
_scrollPager.tag=100;
}
在同一视图控制器中处理如下所示的双击操作
- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer
{
// zoom in
NSLog(@"handleDoubleTap");
if(gestureRecognizer.view == _scrollPager) return;
UIScrollView *doubleTapScroll = [self getImageScroller];
if(doubleTapScroll)
{
//zoom
CGPoint pointInView = [gestureRecognizer locationInView:self.view];
CGFloat newZoomScale = doubleTapScroll.zoomScale * 1.5f;
newZoomScale = MIN(newZoomScale, doubleTapScroll.maximumZoomScale);
CGRect rectToZoomTo = CGRectZero;
CGFloat currentZoomScale = doubleTapScroll.zoomScale;
if(currentZoomScale == 1.0f)
{
rectToZoomTo = [self zoomRectForScrollView:doubleTapScroll withScale:newZoomScale withCenter:pointInView];//CGRectMake(x, y, w, h);
}
else if (currentZoomScale >= 1.0f)
{
rectToZoomTo = [self zoomRectForScrollView:doubleTapScroll withScale:1 withCenter:self.view.center];
}
[doubleTapScroll zoomToRect:rectToZoomTo animated:YES];
}
}
最终处理缩放
#pragma mark Utility methods
- (CGRect)zoomRectForScrollView:(UIScrollView *)scrollView withScale:(float)scale withCenter:(CGPoint)center
{
CGRect zoomRect;
zoomRect.size.height = scrollView.frame.size.height / scale;
zoomRect.size.width = scrollView.frame.size.width / scale;
zoomRect.origin.x = center.x - (zoomRect.size.width / 2.0);
zoomRect.origin.y = center.y - (zoomRect.size.height / 2.0);
return zoomRect;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView1
{
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
if(scrollView == _scrollPager)
{
float currentPage = scrollView.contentOffset.x /scrollView.frame.size.width;
if(currentPage != _current_page)
{
_prev_next_index = _current_page;
_current_page = ceil(currentPage);
[self resetScrollerAtViewIndex:_prev_next_index];
}
}
}
-(UIView *) viewForZoomingInScrollView:(UIScrollView *)scrollView1
{
if(scrollView1 == _scrollPager)
return nil;
else
{
UIScrollView *image_scroll = [self getImageScroller];
if(image_scroll)
if([image_scroll.subviews count]>0)
{
return [image_scroll.subviews objectAtIndex:0];
}
}
return nil;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (UIScrollView *)getImageScroller
{
return [_scrollPager viewWithTag:_current_page];
}
- (void)resetScrollerAtViewIndex:(NSInteger)index
{
UIScrollView *scrollView = [_scrollPager viewWithTag:index];
CGFloat zoomScale = scrollView.zoomScale;
if(zoomScale != 1.0)
[scrollView setZoomScale:1 animated:YES];
}
编辑以便在返回上一页或下一页时缩小 只需替换以下方法
- (void)resetScrollerAtViewIndex:(NSInteger)index
{
//CGFloat zoomScale = 1.0;
UIScrollView *scrollView = [_scrollPager viewWithTag:index];
CGRect rectToZoomTo = CGRectZero;
rectToZoomTo = [self zoomRectForScrollView:scrollView withScale:1 withCenter:self.view.center];
[scrollView zoomToRect:self.view.bounds animated:YES];
[scrollView setContentOffset:CGPointZero];
[scrollView setContentSize:self.view.bounds.size];
}