iPhone OS: Tap status bar to scroll to top doesn't work after remove/add back

Question

Using this method to hide the status bar:

[[UIApplication sharedApplication] setStatusBarHidden:YES animated:YES];

When setting \"hidden\"

Answer 1

I want to add my case, I add an UIWebView on an UIScrollView, as h4xxr had answered on the top:

If there is more than one scrolling view a scrollViewDidScrollToTop message is ignored

So, I get a simply way to make it work on webView: just set the scrollView·s scrollsToTop property false.

And when tap the status bar, it won`t got intercepted by the scrollView, and the webView scrolls to the top!

    UIScrollView *scrollView = [[UIScrollView alloc] init];
    scrollView.frame = self.view.bounds;
    scrollView.scrollsToTop = false; //igore scrollView`s scrollsToTop
    [self.view addSubview:scrollView];

    UIWebView *webView = [[UIWebView alloc] init];
    webView.frame = scrollView.bounds;
    [scrollView addSubview:webView];

Answer 2

You could try setting the ScrollsToTop property to true again after re-showing it:

[currentView setScrollsToTop:YES];

If that's not working, are you definitely only showing one view? If there is more than one scrolling view a scrollViewDidScrollToTop message is ignored...

Answer 3

I just ran across a similar behavior in the app I'm currently working on. In its case, if you load a YouTube video from within a UIWebView, scroll to top stops working for the rest of the application's life cycle. I kind of assume this might happen after loading the movie player as well, but haven't confirmed. That functionality has been around a lot longer and probably has fewer bugs.

Answer 4

In iOS 5.0 you can access the scrollview property of the UIWebView

webView.scrollView.scrollsToTop = YES;

Answer 5

The following fix by Alex worked for me. Thanks!

((UIScrollView *)[[webView subviews] objectAtIndex:0]).scrollsToTop = NO;

Being in a hurry this fix worked great, however given more time I might've subclassed the UIWebView and accessed the protected UIScrollView member directly.

The worry I have with Alex' method is that it assumes that UIScrollView is at index zero of the subviews (encapsulation allows private members to change). Which suggests another solution still:

for (UIView* v in [webView subviews])
{
    if ([v isKindOfClass:[UIScrollView class]])
    {
        (UIScrollView *)v.scrollsToTop = NO;
    }
}

Answer 6

When there are multiple scrollview, you can also set scrollUpToTop to NO for the others scrollview. cf:

setScrollsToTop with multiple UIScrollView classes and/or subclasses(UITableView)