public static Behavior GetMoveDisplayObjectsDownBehavior(string moduleName, List <string> elementNames) { if (string.IsNullOrWhiteSpace(moduleName) || !moduleName.Equals(GlobalData.CurrentModule)) { return(null); } if (elementNames == null || elementNames.Count == 0) { return(null); } string lastElementName = GlobalData.CurrentDisplayObjects[GlobalData.CurrentDisplayObjects.Count - 1].name; int idx = elementNames.FindIndex(lastElementName.Equals); if (idx != -1) { return(null); } return(new Behavior(isReDo => DisplayObjectUtil.MoveDisplayObjectsDownBehavior(moduleName, elementNames), isReUndo => DisplayObjectUtil.MoveDisplayObjectsUpBehavior(moduleName, elementNames), BehaviorType.MoveSelectDisplayObjectsDown)); }