iOS：核心动画之转场动画CATransition

#import "ViewController.h"

@interface ViewController ()
@property (strong,nonatomic)UIImageView *imageView;//图像视图
@property (assign,nonatomic)NSInteger index;       //当前图片的索引
@end

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //设置当前图片为第一张
    self.index = 1;
    
    //初始化图像视图
    self.imageView = [[UIImageView alloc]initWithFrame:self.view.frame];
    self.imageView.contentMode = UIViewContentModeScaleAspectFit;
    [self.imageView setImage:[UIImage imageNamed:[NSString stringWithFormat:@"s%ld.jpg",self.index]]];
    
    
    //允许图像视图进行用户交互
    self.imageView.userInteractionEnabled = YES;
    [self.view addSubview:self.imageView];
    
    
    
    //创建扫动手势
    UISwipeGestureRecognizer *leftswipe = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipe:)];
    //设置扫动方向为向左扫
    leftswipe.direction = UISwipeGestureRecognizerDirectionLeft;
    //添加扫动手势
    [self.imageView addGestureRecognizer:leftswipe];
    
    //创建扫动手势
    UISwipeGestureRecognizer *rightswipe = [[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(swipe:)];
    //设置扫动方向为向右扫
    rightswipe.direction = UISwipeGestureRecognizerDirectionRight;
    //添加扫动手势
    [self.imageView addGestureRecognizer:rightswipe];
}

#pragma mark -扫动手势
-(void)swipe:(UISwipeGestureRecognizer *)sender
{
    //根据手势的方向改变图片的索引,一共5张图片
    if (sender.direction == UISwipeGestureRecognizerDirectionLeft)//向左扫
    {
        if (self.index >1 )
        {
            self.index--;
        }
        else
        {
            self.index = 5;
        }
    }
    else //向右扫
    {
        if (self.index <5)
        {
            self.index++;
        }
        else
        {
            self.index = 1;
        }
    }
    
    //添加转场动画
    CATransition *transition = [[CATransition alloc]init];
    //过渡类型类立方体翻转效果
    transition.type = @"cube";
    //过渡方向为从下往上翻转
    transition.subtype = kCATransitionFromBottom;
    //动画持续时间
    transition.duration = 1.0f;
    //添加转场动画
    [self.imageView.layer addAnimation:transition forKey:@"transition"];

    //设置每一次转场动画后的图像视图的图片
    [self.imageView setImage:[UIImage imageNamed:[NSString stringWithFormat:@"s%ld.jpg",self.index]]];
}