title: How Touch drag enter works?
body: <p>Can anyone give me an example about Touch drag enter to drag from a button to another that triggering both button's event.
  And how does it work?</p>
  
  <p>For example, I want to drag from Do to Fa that event of Do, Re, Mi, Fa are triggered.</p>
  
  <p><a href="https://i.stack.imgur.com/j733u.png" rel="noreferrer"><img src="https://i.stack.imgur.com/j733u.png" alt="iOS Simulator Screenshot"></a></p>
  
  <p>Here is my code:</p>
  
  <pre><code>- (void) setupVC {
  soundBankPlayer = [[SoundBankPlayer alloc] init];
  [soundBankPlayer setSoundBank:@"Piano"];
  arrMusicalNotes = [NSArray arrayWithObjects:@"60", @"62", @"64", @"65", @"67", @"69", @"71", @"72", nil];
  }
  
  
  #pragma mark - Setup Musical Note
  - (IBAction)btnMusicalNoteclick:(id)sender {
      int numOfNote = [[arrMusicalNotes objectAtIndex:((UIButton*)sender).tag] intValue];
      NSLog(@"%i", numOfNote);
      [soundBankPlayer queueNote:numOfNote gain:1.0f];
      [soundBankPlayer playQueuedNotes];
  }
  
  - (IBAction)btnDragOut:(id)sender {
      NSLog(@"Out");
  }
  </code></pre>
  
  <p>Oh I've seen that when i hold click out of Simulator, the method btnDragOut is triggered. And when i drag from out of Simulator to the button, the method of this button is triggered. 
  Now I want the method btnDragOut is triggered when i drag out of a button (finger is still in Simulator). Anyone know that?</p>