Question

I have a paginating scrollview with UIImageView’s inside.
At a point i need to remove some Imageviews to avoid memory-problems.

But at any point i just get a BAD_ACCESS .

for(UIView *subview in [scrollView subviews]) {
  if([subview isKindOfClass:[UIImageView class]]) {
   if ( ([subview tag] != ActualPage) && ([subview tag] != (ActualPage - 1)) && ([subview tag] != (ActualPage+1)) )
   {
       [subview removeFromSuperview];
   }
  } 
}

Basically i wanna remove every subview except the actual page, one back and one forward.

Answer 1

When you have a crash, it is helpful to post the backtrace. Is the crash happening in that loop or elsewhere?

If that loop is executing during display, then you are violating the contract of -removeFromSuperview which explicitly states that it should not be called in the middle of display.

I could also imagine a crash related to causing the subviews to mutate in the middle of enumeration.

Without a backtrace, it is impossible to say conclusively.

In general, if you have code that is using isKindOfClass: for behavior such as this, you have a design oddity that ought to be revisited.