UIScrollView

#pragma mark - 加载视图- (void)viewDidLoad {    [super viewDidLoad];        UIImage *img = [UIImage imageNamed:@"pp.png"];    self.imageView = [[UIImageView alloc]initWithImage:img];//    self.imageView.frame = self.view.frame;//    self.imageView.contentMode = UIViewContentModeScaleAspectFit;        self.scrollView = [[UIScrollView alloc]initWithFrame:self.view.bounds];    self.scrollView.showsHorizontalScrollIndicator = YES;    self.scrollView.showsVerticalScrollIndicator = YES;    //UIScrollViewDelegate    self.scrollView.delegate = self;    [self.scrollView addSubview:self.imageView];    //设置内容大小为图片的大小    self.scrollView.contentSize = self.imageView.bounds.size;        [self.view addSubview:self.scrollView]; }