转场动画 CATransition ，效果惊人

    UISwipeGestureRecognizer *leftSwipeGesture=[[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(leftSwipe:)];
    leftSwipeGesture.direction=UISwipeGestureRecognizerDirectionLeft;
    [self.view addGestureRecognizer:leftSwipeGesture];
    
    UISwipeGestureRecognizer *rightSwipeGesture=[[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(rightSwipe:)];
    rightSwipeGesture.direction=UISwipeGestureRecognizerDirectionRight;
    [self.view addGestureRecognizer:rightSwipeGesture];
    
    UISwipeGestureRecognizer *topSwipeGesture=[[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(topSwipe:)];
    topSwipeGesture.direction=UISwipeGestureRecognizerDirectionUp;
    [self.view addGestureRecognizer:topSwipeGesture];
    
    
    UISwipeGestureRecognizer *bottomSwipeGesture=[[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(bottomSwipe:)];
    bottomSwipeGesture.direction=UISwipeGestureRecognizerDirectionDown;
    [self.view addGestureRecognizer:bottomSwipeGesture];

-(void)leftSwipe:(UISwipeGestureRecognizer *)gesture{
    [self transitionAnimation:1];
}

#pragma mark 向右滑动浏览上一张图片
-(void)rightSwipe:(UISwipeGestureRecognizer *)gesture{
    [self transitionAnimation:2];
}

-(void)topSwipe:(UISwipeGestureRecognizer *)gesture{
    [self transitionAnimation:3];
}

-(void)bottomSwipe:(UISwipeGestureRecognizer *)gesture{
    [self transitionAnimation:4];
}



#pragma mark 转场动画
-(void)transitionAnimation:(NSInteger)direction{
    //1.创建转场动画对象
    CATransition *transition=[[CATransition alloc]init];
    
    //2.设置动画类型,注意对于苹果官方没公开的动画类型只能使用字符串，并没有对应的常量定义
    transition.type=@"rippleEffect";
    
    BOOL bl = YES;
    
    //设置子类型
    if (direction == 1) {
        transition.subtype=kCATransitionFromRight;
        bl = YES;
    }else if (direction == 2) {
        transition.subtype=kCATransitionFromLeft;
        bl = NO;
    }else if (direction == 3) {
        transition.subtype=kCATransitionFromTop;
        bl = YES;
    }else{
         transition.subtype=kCATransitionFromBottom;
        bl = NO;
    }
    
    //设置动画时常
    transition.duration=1.0f;
    
    //3.设置转场后的新视图添加转场动画
    if (bl) {
        currentIndex=(currentIndex+1)%IMAGE_COUNT;
    }else{
        currentIndex=(currentIndex-1+IMAGE_COUNT)%IMAGE_COUNT;
    }
    NSString *imageName=[NSString stringWithFormat:@"%d",(int)currentIndex];
   
    _imageView.image = [UIImage imageNamed:imageName];
    [_imageView.layer addAnimation:transition forKey:@"KCTransitionAnimation1"];
}