title: How to avoid text disappearing when using CGAffineTransform?
body: <p>I want to make a button rotate in my app, and I have the following piece of code:</p>
  
  <pre><code>- (void)setFrameForButton:(UIButton *)ok {
  if ([[UIDevice currentDevice] isWildcat]) {
      if([UIDevice currentDevice].orientation == UIDeviceOrientationPortrait) {
          ok.frame = CGRectMake(244, 840, 280, 20);
          if (wasChanging) ok.transform = CGAffineTransformMakeRotation(M_PI * -0.50);
      }
      else {
          ok.frame = CGRectMake(372, 584, 280, 20);
          if (wasChanging) ok.transform = CGAffineTransformMakeRotation(M_PI * -0.50);
      }
  }
  else {
      ok.frame = CGRectMake(15.0, 375.0 ,280.0, 20.0);
  }
  if (wasChanging) wasChanging = NO;
  }
  
  - (void)window:(id)window willRotateToInterfaceOrientation:(int)orientation duration:(double)duration {
  wasChanging = YES;
  [self setFrameForButton:btn];
  }
  </code></pre>
  
  <p>Although when I rotate the position it should be is changed and after some following rotations the text at my button disappears. What to do?</p>