08

- (void)dealloc {

    [_scrollView release];

    [_pageControl release];

    [super dealloc];

}

 

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {

    //获取滚动视图当前的偏移量

    CGPoint offset = scrollView.contentOffset;

    

    //如果在最后一张，此时往左滑动，跳转到第一张要执行的代码

    if (offset.x + kWidth  > scrollView.contentSize.width) {

        [scrollView setContentOffset:CGPointMake(0, 0) animated:NO];

    }

    if (offset.x < 0) {

        [scrollView setContentOffset:CGPointMake(10 * kWidth, 0) animated:NO];

    }

}

 

//在滚动视图停止滚动时，改变pageControl上面点的位置

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {

    //获取滚动视图当前的偏移量

    CGPoint offset = scrollView.contentOffset;

    

    //计算偏移量与屏幕宽度的关系，也就是偏移了多少倍

    NSInteger page = offset.x / kWidth;

    

    //赋值

    self.pageControl.currentPage = page - 1 < 0 ? 9 : page - 1;

}

 

- (void)click:(UIPageControl *)page {

    self.scrollView.contentOffset = CGPointMake(kWidth * (page.currentPage + 1), 0);

}

 

 

- (void)viewDidLoad {

    [super viewDidLoad];

    

    _scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, kWidth, kHeight)];

    _scrollView.delegate = self;

    _scrollView.contentSize = CGSizeMake(11 * kWidth, kHeight);

    _scrollView.contentOffset = CGPointMake(kWidth, 0);

    _scrollView.showsHorizontalScrollIndicator = NO;

    _scrollView.pagingEnabled = YES;

//    _scrollView.bounces = NO;

    [self.view addSubview:_scrollView];

    

    //在十个label添加之前添加一个与最后一张label一样的视图

    UILabel *firstLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, kWidth, kHeight)];

    firstLabel.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255.0 green:arc4random() % 256 / 255.0 blue:arc4random() % 256 / 255.0 alpha:1.0];

    firstLabel.text = @"9";

    firstLabel.font = [UIFont boldSystemFontOfSize:300];

    firstLabel.textAlignment = NSTextAlignmentCenter;

    [_scrollView addSubview:firstLabel];

    [firstLabel release];

    

    //循环创建十个label

    for (int i = 0; i < 10; i ++) {

        UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(kWidth * (i + 1), 0, kWidth, kHeight)];

        label.text = [NSString stringWithFormat:@"%d",i];

        label.textAlignment = NSTextAlignmentCenter;

        label.font = [UIFont boldSystemFontOfSize:300];

        if (i == 9) {

            label.backgroundColor = firstLabel.backgroundColor;

        } else {

            label.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255.0 green:arc4random() % 256 / 255.0 blue:arc4random() % 256 / 255.0 alpha:1.0];

        }

        [_scrollView addSubview:label];

        [label release];

    }

    

    _pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(30, kHeight - 80, kWidth - 60, 40)];

    _pageControl.numberOfPages = 10;

    _pageControl.currentPage = 0;

    _pageControl.currentPageIndicatorTintColor = [UIColor blackColor];

    _pageControl.pageIndicatorTintColor = [UIColor whiteColor];

    _pageControl.backgroundColor = [UIColor redColor];

    [_pageControl addTarget:self action:@selector(click:) forControlEvents:UIControlEventValueChanged];

    [self.view addSubview:_pageControl];