title: UINavigationController addSubview
body: <p>I have a UINavigationController class, I want to add on a button with the method addSubview but its not working</p>
  
  <pre><code>- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
  {
      self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
      if (self) {
          // Custom initialization
          UIButton *testbtn = [[UIButton alloc] initWithFrame:CGRectMake(20, 90,28,20)];
          [self.view addSubview:testbtn];
      }
      return self;
  }
  </code></pre>