react-navigation的state管理放到application统一的管理中，即所谓的react-navigation和redux一体化，或者集成。
官网doc介绍：https://reactnavigation.org/docs/redux-integration.html

• 添加依赖
• 编写navReducer
• 如何实现一体化
• 编写Root.js入口组件
• 物理键重写
• Demo地址

添加依赖

yarn add react-navigation-redux-helpers
或
npm install --save react-navigation-redux-helpers

编写navReducer

import {NavigationActions} from 'react-navigation'
import {AppNavigator} from "../AppNavigator";

// Start with two routes: The Main screen, with the Login screen on top.
const firstAction = AppNavigator.router.getActionForPathAndParams('Main');
const tempState = AppNavigator.router.getStateForAction(firstAction);
const secondAction = AppNavigator.router.getActionForPathAndParams('Login');
const initiaNavState = AppNavigator.router.getStateForAction(secondAction,tempState);

function nav(state=initiaNavState,action){
    let nextState;
    switch (action.type){
        case 'Login':
            nextState = AppNavigator.router.getStateForAction(
                NavigationActions.back(),
                state
            )
            break;
        case 'Logout':
           nextState = AppNavigator.router.getStateForAction(
                NavigationActions.navigate({ routeName: 'Login' }),
                state
            );
           break;
        case 'BackTwoScreen':
            const key = state.routes[state.index-1].key
            nextState = AppNavigator.router.getStateForAction(
                NavigationActions.back({key:key}),
                state
            )
            break;
        case 'ExitApp':
            nextState = initiaNavState;
            break;
        default:
            nextState = AppNavigator.router.getStateForAction(action, state);
            break;
    }
    // Simply return the original `state` if `nextState` is null or undefined.
    return nextState || state;
}

export default nav;

在reducers文件夹下创建index.js文件，将多个reducer合并。

import {combineReducers} from 'redux'
import nav from './nav'
import auth from './auth'
const AppReducers = combineReducers({
    nav,
    auth
})
export default AppReducers;

如何实现一体化

创建AppNavigator.js文件。

import React from 'react';
import PropTypes from 'prop-types';
import {connect} from 'react-redux'
import {addNavigationHelpers,StackNavigator,NavigationActions } from 'react-navigation'
import {addListener} from "./utils/redux";
...

export const AppNavigator = StackNavigator(
    {
        Login: { screen: LoginScreen },
        Main: { screen: MainScreen },
        Profile: { screen: ProfileScreen },
        ThirdScreen: { screen: ThirdScreen },
    }
)

class AppWithNavigationState extends React.Component{
    static propTypes = {
        dispatch:PropTypes.func.isRequired,
        nav:PropTypes.object.isRequired,
    }

    render(){
        const {dispatch,nav} = this.props;
        return(
            <AppNavigator
                navigation = {addNavigationHelpers({
                    dispatch,
                    state:nav,
                    addListener
                })}
            />
        )
    }
}

const mapStateToProps = state =>({
    nav:state.nav
})

export default connect(mapStateToProps)(AppWithNavigationState);

其中/utils/redux.js文件内容：

import {
    createReactNavigationReduxMiddleware,
    createReduxBoundAddListener
} from 'react-navigation-redux-helpers'

const middleware = createReactNavigationReduxMiddleware(
    'root',
    state => state.nav
)

const addListener = createReduxBoundAddListener('root')

export {
    middleware,
    addListener,
};

编写Root.js入口组件

import React from 'react';
import {Provider} from 'react-redux'
import {createStore,applyMiddleware} from 'redux'
import AppWithNavigationState from './AppNavigator'
import {middleware} from "./utils/redux";
import AppReducers from './reducers/index'

const store = createStore(AppReducers,applyMiddleware(middleware))

export  default class ReduxExampleApp extends React.Component {
    render(){
        return(
            <Provider store = {store}>
                <AppWithNavigationState/>
            </Provider>
        )
    }
}

物理键重写

在AppNavigaor.js文件中，进行物理键监听

import React from 'react';
import { BackHandler,ToastAndroid } from "react-native";
import PropTypes from 'prop-types';
...

export const AppNavigator = StackNavigator(
    {
        Login: { screen: LoginScreen },
        ...
    }
)

class AppWithNavigationState extends React.Component{
     ...  
    componentDidMount() {
        BackHandler.addEventListener("hardwareBackPress", this.onBackPress);
    }
    componentWillUnmount() {
        BackHandler.removeEventListener("hardwareBackPress", this.onBackPress);
    }

    onBackPress = ()=>{
        const { dispatch, nav } = this.props;
        if (nav.index === 0) {
            if (this.lastBackPressed && this.lastBackPressed + 2000 >= Date.now()) {
                //将state设置成第一次启动一致，避免从哪个界面退出，
                  启动时显示哪个界面的bug（杀掉进程启动无该问题）
                dispatch({type:'ExitApp'})
                return false
            }
            ToastAndroid.show('再按一次退出!', 1000);
            this.lastBackPressed = Date.now();
            return true;
        }
        dispatch(NavigationActions.back());
        return true;
    }

    render(){
        const {dispatch,nav} = this.props;
        return(
            <AppNavigator
                navigation = {addNavigationHelpers({
                    dispatch,
                    state:nav,
                    addListener
                })}
            />
        )
    }
}
const mapStateToProps = state =>({
    nav:state.nav
})
export default connect(mapStateToProps)(AppWithNavigationState);

Demo地址

https://github.com/boyrt/react-native-navigation-redux