Question

There’s a private method of the UIScrollView that should allow me to control the speed of a content offset animation. But when I override it in my class like so …

- (void)setContentOffsetAnimationDuration:(CFTimeInterval)value
{
    _contentOffsetAnimationDuration = 10;
}

[self setContentOffset:offset animated:YES];

I get a compiler error like this …

Undefined symbols for architecture armv7:
  "_OBJC_IVAR_$_UIScrollView._contentOffsetAnimationDuration", referenced from:
      -[HistoryScrollView setContentOffsetAnimationDuration:] in HistoryScrollView.o
ld: symbol(s) not found for architecture armv7
collect2: ld returned 1 exit status

Any ideas. I really don’t want to roll some clunky animation code into this. It’s so tantalisingly close to fix.

Answer 1

I think you mean ‘_setContentOffsetAnimationDuration’. Do something like this:

[myScrollView _setContentOffsetAnimationDuration:10];

Although, it will get you rejected from the App Store. The reviewers run static analysers now that detect any usage of private APIs.