public static void ScrollChildToCenter(this ScrollRect sr, GameObject child)
 {
     if (sr && child)
     {
         sr.ScrollChildToCenter((RectTransform)child.transform);
     }
 }
 public static void ScrollChildToCenter(this ScrollRect sr, RectTransform childRtx)
 {
     if (sr && childRtx)
     {
         sr.ScrollChildToCenter(childRtx.position, childRtx.rect.size, childRtx.pivot);
     }
 }