title: UIButton category issues
body: <p>I have made extension for UIButton class. Now if I use it everything works good. But I have another class that create for me array with UIButton objects and here I have some problem.</p>
  
  <p>I have Helper class with method that return for me <strong>array</strong> with UIButton objects.</p>
  
  <p>In ViewController.m in viewDidLoad callback I request for this <strong>array</strong> and also here in ViewController.m I import my UIButton+Extension.m</p>
  
  <p>So, now I have extension for each UIButton object that I will use in ViewController.m</p>
  
  <p>But if I use extension I have got error on method that call </p>
  
  <pre><code>[thumbButton.titleLabel setFont:[UIFont fontWithName:@"Helvetica" size:11.0]];
  </code></pre>
  
  <p>but if I don't use extension this method invoke correct.</p>
  
  <p>this is my UIButton+Extension.h file</p>
  
  <pre><code>#import &lt;UIKit/UIKit.h&gt;
  
  @interface UIButton (extension_button)
  
  - (void)centerButtonToView:(UIView *)view;
  - (UIImage *)cropeImage:(UIImageView *)imageView;
  
  @end
  </code></pre>
  
  <p>this is my UIButton+Extension.m file</p>
  
  <pre><code>#import "UIButton+Extension.h"
  
  @implementation UIButton (extension_button)
  
  - (id)initWithFrame:(CGRect)frame
  {
      self = [super initWithFrame:frame];
      if (self) {
          // Initialization code
      }
      return self;
  }
  
  - (void)centerButtonToView:(UIView *)view {
      CGRect rect = view.frame;
      CGRect rectSelf = self.frame;
      rectSelf.origin.x = (rect.size.width / 2.0f - rectSelf.size.width / 2.0f) + rect.origin.x;
      rectSelf.origin.y = (rect.size.height / 2.0f - rectSelf.size.height / 2.0f) + rect.origin.y;
      self.frame = rectSelf;
  }
  
  - (UIImage *)cropeImage:(UIImageView *)imageView {    
      CGRect rect;
      rect.origin.x = self.frame.origin.x - imageView.frame.origin.x;
      rect.origin.y = self.frame.origin.y - imageView.frame.origin.y;
      rect.size.width = self.frame.size.width;
      rect.size.height = self.frame.size.height;    
      UIGraphicsBeginImageContext(rect.size);
      CGContextRef context = UIGraphicsGetCurrentContext();    
      CGRect drawRect = CGRectMake(-rect.origin.x,-rect.origin.y, imageView.image.size.width, imageView.image.size.height);
      CGContextClipToRect(context, CGRectMake(0, 0, rect.size.width, rect.size.height));
      [imageView.image drawInRect:drawRect];
      UIImage* subImage = UIGraphicsGetImageFromCurrentImageContext();
      UIGraphicsEndImageContext();
      return subImage; 
  }
  
  @end
  </code></pre>
  
  <p>Helper.m (method that return array for me and here I have problem on setFont method)</p>
  
  <pre><code>+ (NSMutableArray *)createThumbnailsForCropSize {
  
      CGFloat width = 0.0f;
      CGFloat start_pos = 0.0f;
  
      if (IS_IPHONE) {
          width = 320.0f;
          start_pos = 62.0f;
      }
      else {
          width = 768.0f;
          start_pos = 286.0f;
      }
  
      NSMutableArray *arr = [[NSMutableArray alloc] init];
      NSArray *resolutionArray = [NSArray arrayWithObjects:@"30x40",@"33x48",@"35x40",@"35x45",@"36x47",@"37x47",
                                  @"40x50",@"40x60",@"43x55",@"45x50",@"50x50",@"50x70", nil];
      NSInteger pos_x = start_pos;
      NSInteger page = 0;
      for (NSInteger idx = 0; idx &lt; 12; idx++) {
          if (idx%3 == 0 &amp;&amp; idx != 0) {
              page++;
              pos_x = start_pos + width * page;
          }
          UIButton *thumbButton = [[UIButton alloc] init];
          [thumbButton setTag:idx];
          [thumbButton setFrame:CGRectMake(pos_x, 13, 60, 60)];
          [thumbButton setTitle:[NSString stringWithFormat:[resolutionArray objectAtIndex:idx]] forState:UIControlStateNormal];
          [thumbButton.titleLabel setFont:[UIFont fontWithName:@"Helvetica" size:11.0]];
          [thumbButton setTitle:@"!00" forState:UIControlStateNormal];
          [thumbButton setBackgroundImage:[UIImage imageNamed:@"block_without_photo.png"] forState:UIControlStateNormal];
          [arr addObject:thumbButton];
          pos_x += 68;
      }
      return arr;
  }
  </code></pre>