title: How to detect rotation for a programatically generated UIView
body: <p>I have a <code>UIView</code> that's programmatically being created:</p>
  
  <pre><code>- (id)initWithFrame:(CGRect)frame {
      self = [super initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height)];
      if (self) {
          self.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:.5];
  
          UIImageView* closeButton = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"modal_close.png"]];
  
          closeButton.frame = CGRectMake(self.frame.size.width*.89, self.frame.size.height*.09, closeButton.frame.size.width, closeButton.frame.size.height);
  
          UIButton* button = [[UIButton alloc] initWithFrame:CGRectMake(self.frame.size.width*.89, self.frame.size.height*.09,20, 20)];
  
          [button addTarget:self action:@selector(close) forControlEvents:UIControlEventTouchUpInside];
  
          UIView* mainView = [[UIView alloc] initWithFrame:CGRectMake(self.frame.size.width*.1,self.frame.size.height*.1,self.frame.size.width*.8,self.frame.size.height*.8)];
  
          mainView.backgroundColor = [UIColor whiteColor];
          _displayMainView = mainView;        
  
          [self addSubview:_displayMainView];
          [self addSubview:closeButton];
          [self addSubview:button];
  
          mainView = nil;
          closeButton = nil;
      }
      return self;
  }
  </code></pre>
  
  <p>How can I detect rotation? This is to act as a modal on top of another existing view. This is an iPad only app, if that matters.</p>