title: Using UIControlEventTouchDragEnter to trigger a button's method... but doesn't work?
body: <p>I am trying to set up a button using UIControlEventTouchDragEnter as the way to trigger the button's method. Specifically, I have a button, and I want the button's method to be triggered if the user presses their finger outside of the button, and drags their finger into the bounds of the button.</p>
  
  <p>According to <a href="http://developer.apple.com/library/ios/#documentation/uikit/reference/UIControl_Class/Reference/Reference.html#//apple_ref/doc/constant_group/Control_Events" rel="nofollow">apple</a>, this event, UIControlEventTouchDragEnter, is: An event where a finger is dragged into the bounds of the control.</p>
  
  <p>However, I can't get the button to trigger. Here is my code:</p>
  
  <pre><code>- (IBAction)touchDragEnter:(UIButton *)sender {
      _samlpe.image = [UIImage imageNamed:@"alternate_pic.png"];
  }
  </code></pre>
  
  <p>So, when touchInto for this button is triggered, the method will change the current image of _sample into this alternate image. If I just use touchUpInside, the image does change to the alternate upon button click.</p>
  
  <p>Does anyone know why this isn't working, or have work-arounds? Thanks!</p>