iOS学习 用scrollView 制作相册album 涉及双击事件

#import <UIKit/UIKit.h>

#define VIEW_WIDTH self.view.bounds.size.width

#define VIEW_HEIGHT self.view.bounds.size.height

#import "ImageScrollView.h"

@interface HomeViewController :UIViewController<UIScrollViewDelegate>{

@private

UIScrollView *_scrollView;

}

@end

@implementation HomeViewController

- (void)viewDidLoad {

[superviewDidLoad];

// Do any additional setup after loading the view.

_scrollView = [[UIScrollViewalloc]initWithFrame:CGRectMake(0,20,VIEW_WIDTH+20,VIEW_HEIGHT)];

_scrollView.tag =101;

[self.viewaddSubview:_scrollView];

_scrollView.backgroundColor = [UIColorblackColor];

_scrollView.pagingEnabled =YES;

_scrollView.contentSize =CGSizeMake((VIEW_WIDTH+20)*4,0);//图片之间设置间隔

_scrollView.delegate =self;

_scrollView.showsHorizontalScrollIndicator =NO;

int _x = 0;

for (int i=0; i<4; i++) {

ImageScrollView *imageSV = [[ImageScrollViewalloc]initWithFrame:CGRectMake(+_x,0,
VIEW_WIDTH,VIEW_HEIGHT)];

imageSV.tag = i;

NSString *imageName = [NSStringstringWithFormat:@"psu-%d.jpeg",i+13];

imageSV.imageView.image = [UIImageimageNamed:imageName];

_x += VIEW_WIDTH+20;

[_scrollView
addSubview:imageSV];

}

}

int pre = 0;

#pragma mark - scrollView Delegate

//翻页时调用

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView

{

int current = scrollView.contentOffset.x/(VIEW_WIDTH+20);

ImageScrollView *imageSV =(ImageScrollView *)[scrollViewviewWithTag:pre];

NSLog(@"%.2f",imageSV.zoomScale);

//判断翻页时图片是否放大缩小

if (current !=
pre && imageSV.zoomScale !=
1)

{

imageSV.zoomScale =
1; //恢复正常大小

}

pre = current;

}

@interface ImageScrollView :UIScrollView<UIScrollViewDelegate>

{

@private

UIImageView *_imageView;

}

@property (nonatomic,readonly,retain)UIImageView *imageView; //只读方式

@end

@implementation ImageScrollView

- (id)initWithFrame:(CGRect)frame{

self = [superinitWithFrame:frame];

if (self) {

self.minimumZoomScale =0.3;

self.maximumZoomScale =3;

self.showsHorizontalScrollIndicator =NO;

self.showsVerticalScrollIndicator =NO;

//创建imageView,与imageScrollview尺寸一样

_imageView = [[UIImageViewalloc]initWithFrame:self.bounds];

[self addSubview:_imageView];

//添加双击事件

UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizeralloc]initWithTarget:selfaction:@selector(zoomInOROut:)];

//点击次数

doubleTap.numberOfTapsRequired =
2;

//将点击事件添加到滑动视图上

[self addGestureRecognizer:doubleTap];

self.delegate =self;

}

return
self;

}

#pragma mark - scrollView Delegate

// 返回一个放大或者缩小的视图

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

{

return_imageView;
//只能处理单张图片

}

#pragma mark - target Action

- (void)zoomInOROut:(UITapGestureRecognizer *)tapGesture{

if (self.zoomScale >=3) {

[selfsetZoomScale:1animated:YES];

}else {

//获取手指点击的位置

CGPoint point = [tapGesture
locationInView:self];

//设置放大的区域

[self zoomToRect:CGRectMake(point.x-40, point.y-40,80,
80) animated:YES];

}

}

@end