lianlianbushell
2012-11-07 02:10
采纳率: 73.8%
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自动滚动scrollview的问题

我的问题是,我要展现给用户的内容放在scrollview中,让内容从上到底自动滚动,我最开始用的是DDAutoscrollview,没实现,哪位好心人帮帮忙吧。不胜感激。

.h文件

 @interface Interface1 : UIViewController {

    IBOutlet UIScrollView *scroller;
    IBOutlet UILabel *warnung;

}


@property (nonatomic, retain) IBOutlet UIScrollView* scrollView;

.m文件

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
    [self.scrollView setContentOffset:bottomOffset animated:NO];

    CGPoint newOffset = self.scrollView.contentOffset;
    newOffset.y = 0;
    [self.scrollView setContentOffset:newOffset animated:YES];
}

- (void)viewDidLoad
{

    [scroller setScrollEnabled:YES];
    [scroller setContentSize:CGSizeMake(320, 420)];

        [super viewDidLoad];
}

thanks

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1条回答 默认 最新

  • prettYYoyic 2012-11-07 03:01
    已采纳

    使用setContentOffset:animated:

    UIScrollView *scrollView = ...;
    CGPoint newOffset = scrollView.contentOffset;
    newOffset.y = 0;
    [scrollView setContentOffset:newOffset animated:YES];
    

    如果你想要开场动画的效果,在scrollView的viewcontroller实现

    - (void)viewDidLoad
    {
        [super viewDidLoad];
    
        // ...
    
        CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
        [self.scrollView setContentOffset:bottomOffset animated:NO];
    }
    - (void)viewDidAppear:(BOOL)animated
    {
        [super viewDidAppear:animated];
    
        CGPoint newOffset = self.scrollView.contentOffset;
        newOffset.y = 0;
        [self.scrollView setContentOffset:newOffset animated:YES];
    }
    

    补充:

    移动的慢点,用timer实现:

    - (void)viewDidLoad
    {
        [super viewDidLoad];
    
        // ...
    
        CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
        [self.scrollView setContentOffset:bottomOffset animated:NO];
    }
    
    
    - (void)viewDidAppear:(BOOL)animated
    {    
        [super viewDidAppear:animated];
    
        CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
    
        //设置延迟时间
        float scrollDurationInSeconds = 4.0;
    
        //计算timer间隔
    
    
        float totalScrollAmount = bottomOffset.y;
        float timerInterval = scrollDurationInSeconds / totalScrollAmount;
    
        [NSTimer scheduledTimerWithTimeInterval:timerInterval target:self selector:@selector(scrollScrollView:) userInfo:nil repeats:YES];
    }
    
    - (void)scrollScrollView:(NSTimer *)timer
    {
        CGPoint newScrollViewContentOffset = self.scrollView.contentOffset;
    
        //向上移动 1px
        newScrollViewContentOffset.y -= 1;
    
    
        newScrollViewContentOffset.y = MAX(0, newScrollViewContentOffset.y);
    
        //如果到顶了,timer中止
        if (newScrollViewContentOffset.y == 0) {
            [timer invalidate];
        }
    
        //最后设置scollView's contentOffset
        self.scrollView.contentOffset = newScrollViewContentOffset;
    }
    
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