CoreAnimation----CAScorllLayer

• 能干嘛？
  你想显示一个大图层里面的一小部分，如：查看大图片，查看一大段数据或者长文本。
• 拿啥来干？

- (void)scrollPoint:(CGPoint)p;  

• 局限
  能像scrollView滚动视图，但并不能有滚动条以及有明确的滚动范围以及其他scrollView的效果( 可能滑动过程中，让视图整体滑出视野)

• 代码示例
  view继承的类：

@implementation shapeView

+ (Class)layerClass {
    return [CAScrollLayer class];
}

- (void)setUp {
    self.layer.masksToBounds = YES;
    
    UIPanGestureRecognizer *recognizer = nil;
    recognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
    [self addGestureRecognizer:recognizer];
}

- (id)initWithFrame:(CGRect)frame {
    if((self = [super initWithFrame:frame])) {
        [self setUp];
    }
    return self;
}

- (void)awakeFromNib {
    [self setUp];
}

- (void)pan:(UIPanGestureRecognizer *)recognizer {
    CGPoint offset = self.bounds.origin;
    offset.x -= [recognizer translationInView:self].x;
    offset.y -= [recognizer translationInView:self].y;
    
    [(CAScrollLayer *)self.layer scrollToPoint:offset];
    
    [recognizer setTranslation:CGPointZero inView:self];
}
@end

viewController:

- (void)viewDidLoad {
    [super viewDidLoad];
    
    UIImage *image = [UIImage imageNamed:@"00000"];
    UIImageView *iv = [[UIImageView alloc] initWithImage:image];
    [self.clipView addSubview:iv];  
}

效果图：