如何在 Flutter 的 State 中使用 2 个 mixin

我有国家班

class ListScreenState extends State<ListScreen>...

我想使用AutomaticKeepAliveClientMixin(以防止包含这些屏幕的TabBar被丢弃)和TickerProviderStateMixin，因为我有需要它的动画控制器.但是当我把这两个Mixin都放在这个类中时，会出现一个错误:

error: Type parameters could not be inferred for the mixin 'TickerProviderStateMixin' because the base class implements the mixin's supertype constraint 'State<T>' in multiple conflicting ways (mixin_inference_inconsistent_matching_classes at [myapp] lib/trips/ListScreen.dart:21)

我真的找不到一个很好的解释如何在一个类中使用mixin.感谢您的帮助.

以下是完整的代码:

import 'package:flutter/widgets.dart';    

class ListScreen extends StatefulWidget {

  @override
  State<StatefulWidget> createState() {
    return ListScreenState();
  }
}

 class ListScreenState extends State<ListScreen>
    with AutomaticKeepAliveClientMixin, TickerProviderStateMixin {

  AnimationController controller;

  @override
  void initState() {
    super.initState();

    controller = AnimationController(
        duration: const Duration(milliseconds: 250), vsync: this);

  }

  @override
  bool get wantKeepAlive => true;
}

DART特别抱怨添加了TickerProviderStateMixin.如果我删除AutomaticKeepAliveClientMixin，它就不会再抱怨了.