Agularjs妙用双向数据绑定实现手风琴效果

$scope.toogleShowDtl = function (item, e) {
       //阻止事件冒泡
       e.stopPropagation();
      for (var i = 0; i < $scope.OrderHdr.length; i++) {
        if ($scope.OrderHdr[i].Bill_Hdr_Id != item.Bill_Hdr_Id) {
          $scope.OrderHdr[i].mxShow = false;
          $scope.OrderHdr[i].iconChange = "glyphicon glyphicon-menu-down";
        }
      }
      switch (item.mxShow) {
        case undefined:
          item.mxShow = true;
          item.iconChange = "glyphicon glyphicon-menu-up";
          break;
        case true:
          item.mxShow = false;
          item.iconChange = "glyphicon glyphicon-menu-down";
          break;
        case false:
          item.mxShow = true;
          item.iconChange = "glyphicon glyphicon-menu-up";
          break;
        default:
          item.mxShow = false;
          item.iconChange = "glyphicon glyphicon-menu-down";
          break;
      }
    }

<div class="col-sm-12 detial_box" ng-click="selectHdr($index)" ng-class="{ dtl_select : $index == selectedIndex }">
  <div class="col-sm-3" style="margin-top:60px; ">
   <button class="btn btn-primary" ng-click="toogleShowDtl(o,$event)">详情</button>
  </div>
  <div class="down_img">
    <span class="{{o.iconChange}} glyphicon glyphicon-menu-down" ng-click="toogleShowDtl(o,$event)"></span>
  </div>
</div>
<div class="col-sm-12 mx_box check-element animate-show-hide" ng-show="o.mxShow">
  <!--明细内容-->
</div>

class="{{o.iconChange}} glyphicon glyphicon-menu-down"