核心动画的使用

1、引导页动画

• 1.1 ViewController.m

  @interface ViewController () <UIScrollViewDelegate>
  
  @property (weak, nonatomic) IBOutlet UIImageView *sunView;
  @property (weak, nonatomic) IBOutlet UIImageView *personView;
  
  @end
  
  @implementation ViewController
  
  - (void)viewDidLoad {
  	[super viewDidLoad];
  
  	UIImage *bgImage = [UIImage imageNamed:@"520_userguid_bg"];
  
  	// ScrollView
  	UIScrollView *scorollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
  	scorollView.contentSize = bgImage.size;
  	scorollView.delegate = self;
  	scorollView.decelerationRate = 0.5;
  	[self.view insertSubview:scorollView atIndex:0];
  
  	// bg
  	UIImageView *bgImageView = [[UIImageView alloc] initWithImage:bgImage];
  	CGRect rect = bgImageView.frame;
  	rect.size.height = self.view.bounds.size.height;
  	bgImageView.frame = rect;
  	[scorollView addSubview:bgImageView];
  
  	// cg
  	UIImage *cgImage = [UIImage imageNamed:@"520_userguid_cg"];
  	UIImageView *cgImageView = [[UIImageView alloc] initWithImage:cgImage];
  	rect = cgImageView.frame;
  	rect.size.height = self.view.bounds.size.height;
  	cgImageView.frame = rect;
  	[bgImageView addSubview:cgImageView];
  
  	// fg
  	UIImage *fgImage = [UIImage imageNamed:@"520_userguid_fg"];
  	UIImageView *fgImageView = [[UIImageView alloc] initWithImage:fgImage];
  	rect = cgImageView.frame;
  	rect.size.height = self.view.bounds.size.height;
  	fgImageView.frame = rect;
  	[bgImageView addSubview:fgImageView];
  
  	// cloud
  	UIImage *cloudImage = [UIImage imageNamed:@"520_userguid_cloud"];
  	UIImageView *cloudImageView = [[UIImageView alloc] initWithImage:cloudImage];
  	[bgImageView addSubview:cloudImageView];
  }
  
  // 只要一滚动就会调用
  - (void)scrollViewDidScroll:(UIScrollView *)scrollView {
  
  	// 获取 scrollView 偏移量
  	CGFloat offsetX = scrollView.contentOffset.x;
  
  	int intOffsetX = (int)offsetX;
  
  	// 切换人物的图片
  	NSString *imageName = [NSString stringWithFormat:@"520_userguid_person_taitou_%d", (intOffsetX % 2 + 1)];
  	self.personView.image = [UIImage imageNamed:imageName];
  
  	// 旋转小太阳
  	self.sunView.transform = CGAffineTransformRotate(self.sunView.transform, 5 / 180.0 * M_PI);
  }
  
  @end
  

• 1.2 效果

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