title: why UIWebView should not be subclassed?
body: <p>From the <a href="http://developer.apple.com/library/ios/#documentation/uikit/reference/UIWebView_Class/Reference/Reference.html" rel="nofollow">UIWebView</a>, The UIWebView class should not be subclassed.</p>
  
  <p>I just want to know why. There is no more detail about this.</p>
  
  <p>Because I met a memory out issue in my project, which create one extended UIWebView, which could cause memory out issue. Otherwise, just create the UIWebView instance will not  cause the issue.</p>
  
  <p>That is why I want to address this problem and try to analyze more.</p>
  
  <p>Thanks for the guy to give some comments in terms of the design pattern with MVC.
  I hope to close this once get some comments for memory management. 
  Thanks,</p>