text: import {combineReducers} from 'redux'
  import theme from './theme'
  import popular from './popular'
  import trending from './trending'
  import favorite from './favorite'
  import language from './language'
  import search from './search'
  import {rootCom, RootNavigator} from '../navigator/AppNavigators';
  
  //1.指定默认state
  const navState = RootNavigator.router.getStateForAction(RootNavigator.router.getActionForPathAndParams(rootCom));
  
  /**
   * 2.创建自己的 navigation reducer，
   */
  const navReducer = (state = navState, action) => {
      const nextState = RootNavigator.router.getStateForAction(action, state);
      // 如果`nextState`为null或未定义，只需返回原始`state`
      return nextState || state;
  };
  
  /**
   * 3.合并reducer
   * @type {Reducer<any> | Reducer<any, AnyAction>}
   */
  const index = combineReducers({
      nav: navReducer,
      theme: theme,
      popular: popular,
      trending: trending,
      favorite: favorite,
      language: language,
      search: search,
  });
  
  export default index;