title: UITapGestureRecognizer doesn't fire up on UIView Subclass
body: <p>I've created a custom subclass of UIView because I needed to override drawRect method.
  I try to add a UITapGestureRecognizer to it, but this doesn't work for me.
  Here, the code of my ViewController:</p>
  
  <pre><code>MyCustomView *customView = [[MyCustomView alloc] initWithFrame:CGRectFrame(0, 30, 30, 30)];
  [customView setUserInteractionEnabled:YES];
  
  UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(doSomething)];
  [customView addGestureRecognizer:tapGestureRecognizer];
  </code></pre>
  
  <p>I don't understand why when I touch my UIView subclass object, the gesture recognizer doesn't fire up.</p>
  
  <p>Thanks a lot in advance !</p>
  
  <p><strong>FIXED IT OUT !</strong></p>
  
  <p>My view was on a UIImageView, and that UIImageView hadn't the <code>userInteractionEnabled</code> set to YES.</p>