Scroll View not functioning IOS 7

问题:

I have a scrollview inside which i have 20 UItextviews. The scrollview is not working. I have set the following in viewdidload.

self.MainScroll.contentSize = CGSizeMake(320, 1800);

Still it doesn't scroll. However, if i give bounce vertically, it just bounces. My scrollview is a child of the main UIview of dimension 320*600. Please guide how to enable the scroll!!

回答1:

There are two ways you can get the scrolling to work.

Approach 1 (with code):

1) Pin UIScrollView to the sides of its parent view, as mentioned below.

2) Set content size of your scroll view in viewDidLayoutSubviews:

- (void)viewDidLayoutSubviews {
    self.MainScroll.contentSize = CGSizeMake(320, 1800);
}

Approach 2 (pure IB, no code required):

1) Setting contentSize is not required if using AutoLayout. You need to pin your UIScrollView to the parent view as mentioned below:

2) Then add another UIView inside UIScrollView to act as a content view and pin it to the UIScrollView and move all controls inside this content view:

3) Pin content view to its parent scroll view as mentioned below:

4) Set your UIViewController's Simulated Metrics to Freeform (this is important):

5) Size your content UIView to your desired height (obviously important too):

Apple article explaining UIScrollView and AutoLayouts: https://developer.apple.com/library/content/technotes/tn2154/_index.html

回答2:

Update the content size after some delay as below.

- (void)viewDidLayoutSubviews {
    [self performSelector:@selector(updateContentSize)
               withObject:nil
               afterDelay:0.25];

}

-(void)updateContentSize{
    UIView *viewLast = [viewContent viewWithTag:100];
    scrollViewAd.contentSize = CGSizeMake([UIScreen mainScreen].bounds.size.width, CGRectGetMaxY(viewLast.frame));
}