Automatic scrolling scrollview

问题:

I have a question. I want to display the user some content in a UIScrollView. I want to autoscroll the UIScrollView fast from bottom to top (like in the apple stores iPad). I tried to use DDAutoscrollview (If someone knows), but it doesn't work for me. Do have someone a solution for me to autoscroll a UIScrollView? Any code snippets would be nice.

.h

@interface Interface1 : UIViewController {

    IBOutlet UIScrollView *scroller;
    IBOutlet UILabel *warnung;

}

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

.m

- (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.

---

> THUMBS UP FOR THE AWNSER THAT WAS GIVEN BY TOBI!!!

---

回答1:

Just use setContentOffset:animated:

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

Edit:

To use it like some kind of start animation you could do this in the scrollView's view controller:

- (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];
}

Edit 2 / 3:

To make the scrolling happen slower, use this:

- (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];

    float scrollDuration = 4.0;

    [UIView animateWithDuration:scrollDuration animations:^{
        self.scrollView.contentOffset = CGPointMake(self.scrollView.contentOffset.x, 0);
    }];
}