ios-自動滾動scrollview的問題

自動滾動scrollview的問題

我的問題是，我要展現給用戶的內容放在scrollview中，讓內容從上到底自動滾動，我最開始用的是DDAutoscrollview，沒實現，哪位好心人幫幫忙吧。不勝感激。

.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

最佳回答：

使用setContentOffset:animated:

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

如果你想要開場動畫的效果，在scrollView的viewcontroller實現

- (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];
}

補充：

移動的慢點，用timer實現：

- (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);

    //設置延遲時間
    float scrollDurationInSeconds = 4.0;

    //計算timer間隔


    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;

    //向上移動 1px
    newScrollViewContentOffset.y -= 1;


    newScrollViewContentOffset.y = MAX(0, newScrollViewContentOffset.y);

    //如果到頂了，timer中止
    if (newScrollViewContentOffset.y == 0) {
        [timer invalidate];
    }

    //最後設置scollView's contentOffset
    self.scrollView.contentOffset = newScrollViewContentOffset;
}