iOS，Objective-C，相册功能的实现。

#import "ViewController.h"

#define kuan [UIScreen mainScreen].bounds.size.width
#define gao [UIScreen mainScreen].bounds.size.height
@interface ViewController ()<UIScrollViewDelegate>
@property (weak, nonatomic) IBOutlet UIScrollView *huaKuang;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    //设置contentSize
    _huaKuang.contentSize=CGSizeMake((kuan)*4, gao);
    _huaKuang.backgroundColor=[UIColor blackColor];
    //设置分页
    _huaKuang.pagingEnabled=YES;
    //隐藏滚动条
    //滚动时是否显示水平滚动条
    _huaKuang.showsHorizontalScrollIndicator=NO;
    //滚动时是否显示垂直滚动条
    _huaKuang.showsVerticalScrollIndicator=NO;
    //设置代理,需要遵循代理协议<UIScrollViewDelegate>，写在@interface ViewController ()的后面
    _huaKuang.delegate=self;
    //添加子视图，因为是多个所以写了一个方法来实现添加
    [self tianJianZiShiTu];
}
-(void)tianJianZiShiTu
{
    //假如有六个图片，就要创建六个UIScrollView和六个UIImageView,并且找到六个图片
    for(int i=0;i<3;i++)
    {
        //创建UIScrollView
        //为了区分开不同的照片加一个20黑边，需要设置ScrollViewscroll View中的Left和View中的Width
        UIScrollView *uisv=[[UIScrollView alloc] initWithFrame:CGRectMake((kuan+20)*i, 0, kuan, gao)];
        //把创建完成的添加到总的那个UIScrollView上
        [_huaKuang addSubview:uisv];
        //创建UIImageView
        UIImageView *uiiv=[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, kuan, gao)];
        //把创建的UIImageView添加到UIScrollView中
        [uisv addSubview:uiiv];
        //设置UIImageView的图片
         NSString *imageName = [NSString stringWithFormat:@"new_feature_%d",i + 1];
        uiiv.image=[UIImage imageNamed:imageName];
        //设置tag值
        uiiv.tag=1000;
        //设置UIScrollView的代理
        uisv.delegate=self;
        //设置缩放范围
        uisv.minimumZoomScale=0.5;
        uisv.maximumZoomScale=1.5;
        //定义点击事件
        UITapGestureRecognizer *tap=[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dianJiShiJian:)];
        //设置有效点击数(就是双击)
        tap.numberOfTapsRequired=2;
        //添加到UIScrollView中
        [uisv addGestureRecognizer:tap];
    }
}
-(void)dianJiShiJian:(UITapGestureRecognizer *)tap
{
    //获取点击事件的view
    UIScrollView *uisv1=(UIScrollView *)tap.view;
    if(uisv1.zoomScale!=1.0)
   {
       [uisv1 setZoomScale:1.0 animated:YES];
       return ;
   }
    CGPoint location=[tap locationInView:tap.view];
    CGRect rect=CGRectMake(location.x-100, location.y-100, 200, 200);
    [uisv1 zoomToRect:rect animated:YES];
}
//指定缩放的视图
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{
    if (scrollView == _huaKuang) {
        return nil;
    }
    UIImageView *imageView = (UIImageView *)[scrollView viewWithTag:1000];
    return imageView;
}

//滚动结束，把所有的缩放视图的缩放比例置为1.0
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
    if (scrollView == _huaKuang) {
        for (id obj in _huaKuang.subviews) {
            if ([obj isKindOfClass:[UIScrollView class]]) {
                UIScrollView *scaleSC = (UIScrollView *)obj;
                scaleSC.zoomScale = 1.0;
            }
        }
    }
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

@end