He intentado descartar la vista de hoja de formulario modal en el toque externo en iOS 8 sin suerte, he intentado este código

UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapBehind:)];

[recognizer setNumberOfTapsRequired:1];
recognizer.cancelsTouchesInView = NO; //So the user can still interact with controls in the modal view
[self.view.window addGestureRecognizer:recognizer];

- (void)handleTapBehind:(UITapGestureRecognizer *)sender
{

if (sender.state == UIGestureRecognizerStateEnded)
 {
   CGPoint location = [sender locationInView:nil]; //Passing nil gives us coordinates in the window

 //Then we convert the tap's location into the local view's coordinate system, and test to see if it's in or outside. If outside, dismiss the view.

    if (![self.view pointInside:[self.view convertPoint:location fromView:self.view.window] withEvent:nil]) 
    {
       // Remove the recognizer first so it's view.window is valid.
      [self.view.window removeGestureRecognizer:sender];
      [self dismissModalViewControllerAnimated:YES];
    }
 }
}

Pero no detecta los clics de la vista externa, ¿alguna sugerencia?