@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    //创建一个scrollview

    UIScrollView *_scrollview = [[UIScrollView alloc]init];

    _scrollview.frame = CGRectMake(,,,);

    _scrollview.backgroundColor = [UIColor grayColor];

    [self.view addSubview:_scrollview];

    UIImageView *bgimage = [[UIImageView alloc]init];

    bgimage.image = [UIImage imageNamed:@"guide.png"];

    CGFloat height = bgimage.image.size.height;

    CGFloat width  = bgimage.image.size.width;

    bgimage.frame  = CGRectMake(, , width, height);

    [_scrollview addSubview:bgimage];

    //scrollview滑动的范围，加上此句后出现水平及纵向拖动条

    _scrollview.contentSize = bgimage.image.size;

    //拖动到结束时增加弹簧效果

    _scrollview.bounces = TRUE;

    //水平拖动条显示

    _scrollview.showsHorizontalScrollIndicator = YES;

    //垂直拖动条显示

    _scrollview.showsVerticalScrollIndicator = YES;

    //拖动条的风格

    // UIScrollViewIndicatorStyleDefault, 默认风格

    // UIScrollViewIndicatorStyleBlack,   黑色风格

    // UIScrollViewIndicatorStyleWhite    白色风格

    _scrollview.indicatorStyle = UIScrollViewIndicatorStyleWhite;

    _scrollview.pagingEnabled = YES;

}

@end