iOS iCarousel实现视图水平滑动（中间放大，两边缩小）选择影片效果 ...

参考资料：http://www.jianshu.com/p/718ef0e3b611

使用到的第三方库：iCarousel。

使用：iCarousel使用方式与UITableView相似，具体看代码。

#import "ViewController.h"
#import "iCarousel.h"

@interface ViewController ()<iCarouselDelegate,iCarouselDataSource>

@property (nonatomic, strong) iCarousel *filmCarousel;
@property (nonatomic, strong) NSMutableArray *filmImageNameArr;
@property (nonatomic, strong) NSMutableArray *filmNameArr;
@property (nonatomic, strong) UIView *selectView;
@property (nonatomic, strong) UILabel *filmNameLab;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor whiteColor];

    [self.view addSubview:self.filmCarousel];

    self.filmNameLab = [[UILabel alloc]initWithFrame:CGRectMake(0, CGRectGetMaxY(self.filmCarousel.frame), self.view.frame.size.width, 44)];
    self.filmNameLab.font = [UIFont systemFontOfSize:20];
    self.filmNameLab.textAlignment = NSTextAlignmentCenter;
    [self.view addSubview:self.filmNameLab];
}

#pragma mark - iCarouselDataSource
-(NSInteger)numberOfItemsInCarousel:(iCarousel *)carousel{
    return self.filmImageNameArr.count;
}

-(UIView *)carousel:(iCarousel *)carousel viewForItemAtIndex:(NSInteger)index reusingView:(UIView *)view{

    UIImage *image = [UIImage imageNamed:[self.filmImageNameArr objectAtIndex:index]];
    if (view == nil) {
        view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 80, 120)];
        view.backgroundColor = [UIColor clearColor];

        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(2, 2, 76, 116)];
        imageView.tag = 1000+index;
        [view addSubview:imageView];
    }
    UIImageView *imageView = [view viewWithTag:1000+index];
    imageView.image = image;

    return view;
}

#pragma mark - iCarouselDelegate
- (void)carouselDidEndScrollingAnimation:(iCarousel *)carousel{
    NSLog(@"___1 %lu",carousel.currentItemIndex);
    UIView *view = carousel.currentItemView;
    view.backgroundColor = [UIColor whiteColor];
    self.selectView = view;
    self.filmNameLab.text = self.filmNameArr[carousel.currentItemIndex];
}

- (void)carouselDidScroll:(iCarousel *)carousel{
    NSLog(@"___2 %lu",carousel.currentItemIndex);
    if (self.selectView != carousel.currentItemView) {
        self.selectView.backgroundColor = [UIColor clearColor];
        UIView *view = carousel.currentItemView;
        view.backgroundColor = [UIColor whiteColor];

        self.filmNameLab.text = self.filmNameArr[carousel.currentItemIndex];
    }
}

- (void)carouselCurrentItemIndexDidChange:(iCarousel *)carousel{
    NSLog(@"___3 %lu",carousel.currentItemIndex);
    self.selectView = carousel.currentItemView;
}

-(CATransform3D)carousel:(iCarousel *)carousel itemTransformForOffset:(CGFloat)offset baseTransform:(CATransform3D)transform{
    static CGFloat max_sacle = 1.0f;
    static CGFloat min_scale = 0.8f;
    if (offset <= 1 && offset >= -1) {
        float tempScale = offset < 0 ? 1+offset : 1-offset;
        float slope = (max_sacle - min_scale) / 1;

        CGFloat scale = min_scale + slope*tempScale;
        transform = CATransform3DScale(transform, scale, scale, 1);
    }else{
        transform = CATransform3DScale(transform, min_scale, min_scale, 1);
    }

    return CATransform3DTranslate(transform, offset * self.filmCarousel.itemWidth * 1.4, 0.0, 0.0);
}

#pragma mark - LazyLoad
-(iCarousel *)filmCarousel{
    if (_filmCarousel == nil) {
        _filmCarousel = [[iCarousel alloc] initWithFrame:CGRectMake(0, self.view.frame.size.height / 2 - 100, self.view.frame.size.width, 150)];
        _filmCarousel.delegate = self;
        _filmCarousel.dataSource = self;
        _filmCarousel.backgroundColor = [UIColor lightGrayColor];
        _filmCarousel.bounces = NO;
        _filmCarousel.pagingEnabled = YES;
        _filmCarousel.type = iCarouselTypeCustom;
    }
    return _filmCarousel;
}

- (NSMutableArray *)filmImageNameArr{
    if (!_filmImageNameArr) {
        _filmImageNameArr = [NSMutableArray array];
        for (int i = 1; i< 6; i++) {
            [_filmImageNameArr addObject:[NSString stringWithFormat:@"defaultFilm%d",i]];
        }
    }
    return _filmImageNameArr;
}

- (NSMutableArray *)filmNameArr{
    if (!_filmNameArr) {
        _filmNameArr = [NSMutableArray array];
        for (int i = 1; i< 6; i++) {
            [_filmNameArr addObject:[NSString stringWithFormat:@"film %d",i]];
        }
    }
    return _filmNameArr;
}

@end