Adding Scrollbar to UIScrollView Subclass

[ghost]

Hey,

I tried to implement the VerticalScrollBar in a UIScrollViewSubclass with the following code:

• (void) initVerticalScrollBarForScrollView
  {
  // NOTE: Make sure vertical scroll bar is on top of the scroll view
  [self setVerticalScrollBar:[[WKVerticalScrollBar alloc] initWithFrame:self.frame]];
  [self.verticalScrollBar setScrollView:self];

  [self addSubview:self.verticalScrollBar];
  [self bringSubviewToFront:self.verticalScrollBar];

  [self setAccessoryView:[[WKAccessoryView alloc] initWithFrame:CGRectMake(0, 0, 65, 30)]];
  [self.accessoryView setForegroundColor:[UIColor colorWithWhite:0.2f alpha:1.0f]];
  [self.verticalScrollBar setHandleAccessoryView:self.accessoryView];
  }

The ScrollBar is shown correctly but when I scroll vertically the scrollbar doesn't scroll and stays sticky at the top of the UIScrollView.

I have implemented WKVerticalScrollView before, inside an UIViewController and it worked perfectly. Why stays the scrollbar sticky at the top, when using it inside of UIScrollView subclass?
Any ideas?

Greetz!