title: Problems when overriding scrollViewDidScroll, but not all the other methods of UIScrollViewDelegate
body: <p>Okay, so I did all the research for this issue but none of the existing solutions seem to address my problem, so here it is:</p>
  
  <ul>
  <li>I have a custom class that extends UIScrollView (and contains a UIView)</li>
  <li>I'd like to override the scrollViewDidScroll method from UIScrollViewDelegate (but not all the methods)</li>
  </ul>
  
  <p>I have already tried implementing the code from this issue: <a href="https://stackoverflow.com/questions/9978279/how-to-subclass-uiscrollview-and-make-the-delegate-property-private">How to subclass UIScrollView and make the delegate property private</a> but for some reason, it doesn't do anything (the custom method that was overridden never gets called). I also know that you don't have to implement all the methods from UIScrollViewDelegate if you create a custom delegate class that implements the protocol (as per <a href="https://stackoverflow.com/questions/6644630/iphone-do-i-need-to-implement-all-methods-for-uiscrollviewdelegate-or-any-dele">iPhone: Do I need to implement all methods for UIScrollViewDelegate (or any delegate)</a>) - but when I do this:</p>
  
  <p><strong>MyScrollViewDelegate.h</strong></p>
  
  <pre><code>@interface MyScrollViewDelegate: NSObject &lt;UIScrollViewDelegate&gt;
  
  -(void)scrollViewDidScroll:(UIScrollView *)scrollView;
  
  @end
  </code></pre>
  
  <p><strong>MyScrollViewDelegate.m</strong></p>
  
  <pre><code>@implementation MyScrollViewDelegate
  
  -(void)scrollViewDidScroll:(UIScrollView *)scrollView
  {
      NSLog(@"Custom scrollViewDidScroll called.");
      // -- some more custom code here --
      // ...
  }
  
  @end
  </code></pre>
  
  <p><strong>In the subclass which extends UIScrollView</strong></p>
  
  <pre><code>// this scrollview is initiated by the NIB
  - (void)awakeFromNib
  {
      ...
      [self setDelegate:[[MyScrollViewDelegate alloc] init]];
  }
  </code></pre>
  
  <p>But while it compiles and runs, when I try to scroll the scrollable view, it crashes with EXC_BAD_ACCESS and a cryptic "(lldb)" message in the debug console.</p>
  
  <p>So I'm bit at a loss here what to do.</p>