Converts between localPosition and anchoredPosition for a RectTransform.

GetLocalToAnchoredPositionOffset.cs

// Add this to convert a local position to an anchored position
public static Vector2 GetLocalToAnchoredPositionOffset(this RectTransform rectTransform) {
	var parentRT = (RectTransform) rectTransform.parent;
	var pivotAnchor = new Vector2(Mathf.LerpUnclamped(rectTransform.anchorMin.x, rectTransform.anchorMax.x, rectTransform.pivot.x), Mathf.LerpUnclamped(rectTransform.anchorMin.y, rectTransform.anchorMax.y, rectTransform.pivot.y));
	return -parentRT.rect.size * (pivotAnchor - parentRT.pivot);
}

// Add this to convert a local position to an anchored position
public static Vector2 GetAnchoredToLocalPositionOffset(this RectTransform rectTransform) {
	return -rectTransform.GetLocalToAnchoredPositionOffset();
}