NoSuchMethodError: The method '>' was called on null

[CatEatFishs]

你好，我1.2.4版本还是出现这个问题，我在曾经的issues 中看到过，但是我还是出现这个问题，
new EasyRefresh( key: _easyRefreshKey, refreshHeader: MaterialHeader( key: _headerKey, ), refreshFooter: MaterialFooter( key: _footerKey, ), child: CustomScrollView( slivers: <Widget>[ SliverList( delegate: SliverChildBuilderDelegate( (BuildContext context, int index) { return OrganizationItem( index: index, followButtonHidden: true, item: list[index]); }, childCount: list==null ? 0 : list.length, ), ) ], ), onRefresh: () async { await new Future.delayed(const Duration(seconds: 1), () { list.clear(); this.isShowLoading=false; isMore=true; pageNum='1'; followListRequest(studentId, pageNum, pageSize); }); }, loadMore: () async { await new Future.delayed(const Duration(seconds: 1), () { if(isMore){ this.isShowLoading=false; pageNum=(int.parse(pageNum)+1).toString(); // followListRequest(studentId, pageNum, pageSize); }else{ Alert.toast(context, '已加载完全部' , position: ToastPosition.center, duration: ToastDuration.short); } }); }, ),
这是我的代码，上拉加载就报错NoSuchMethodError: The method '>' was called on null，麻烦解决一下

[xuelongqy]

可以定位一下错误吗？因为我没有遇到过这个情况。我的猜想是否在body.semanticChildCount > this._itemCount的判断出错？

[xuelongqy]

或者给我一个简单运行的示例

[xuelongqy]

1.2.5已解决