React Native中的useEffect用“ flux”而不是“ React-Navigation”?

问题描述

我正在尝试在React-Native中使用'useEffect'钩子。我正在尝试在场景/脚本之间更改“上下文”变量。我正在使用“ React-Native-Router-Flux”进行导航。这是一些代码:

LogContext.js

import React,{ useState } from 'react'

export const LogContext = React.createContext({
  set: "en",login: "false"
})

export const LogContextProvider = (props) => {

  const setLog = (login) => {
    setState({set: "jp",login: login})
  }

  const initState = {
    set: "en",login: "false"
  } 

  const [state,setState] = useState(initState)

  return (
    <LogContext.Provider value={state}>
      {props.children}
    </LogContext.Provider>
  )
}

Proceed.js

import React,{ useState,useContext,createContext } from 'react'
import { TouchableOpacity,Text } from 'react-native'
import { Actions } from 'react-native-router-flux'

import { LogContextProvider,LogContext } from './LogContext'

const Proceed = (props) => {
 const status = useContext(LogContext);

   const goToHome = () => {
      Actions.video()
   }

  React.useEffect(() => {
    const unsubscribe = this.props.navigation.addListener('willFocus',() => {
      // The screen is focused
      // Call any action
      status.setState({ set: 'ddd',login: 'true' })
      console.log('didFocus');
    });

    // Return the function to unsubscribe from the event so it gets removed on unmount
    return unsubscribe;
  },Actions.home());

   return (
      <TouchableOpacity style = {{ margin: 128 }} onPress = {goToHome}>
         <Text>This is Proceed</Text>
      </TouchableOpacity>
   )
}
export default Proceed

上面的代码在“ status.setData”行上引发错误。如果我使用“ React.Navagation”而不是“ React-Navigation-Router-Flux”的替代版本,则以下代码将起作用。所以基本上我想将下面的代码转换为使用“ Flux”而不是“ React-Navigation”。例如:

function ProceedScreen({ navigation }) {
  const status = React.useContext(LogContext);

  React.useEffect(() => {
    const unsubscribe = navigation.addListener('focus',() => {
      // The screen is focused
      // Call any action
      status.setData({ set: 'ddd',login: 'true' })
    });

    // Return the function to unsubscribe from the event so it gets removed on unmount
    return unsubscribe;
  },[navigation]);

  return (
    <View style={{ flex: 1,alignItems: 'center',justifyContent: 'center' }}>
      <Text>Video Screen</Text>
      <Button title="Logout" onPress={() => navigation.navigate('Logout')} />
      <Text>Passed SET: {JSON.stringify(status.data.set)}</Text>
      <Text>Passed LOGIN: {JSON.stringify(status.data.login)}</Text>
    </View>
  );
}

在此先感谢您的任何建议。

解决方法

暂无找到可以解决该程序问题的有效方法,小编努力寻找整理中!

如果你已经找到好的解决方法,欢迎将解决方案带上本链接一起发送给小编。

小编邮箱:dio#foxmail.com (将#修改为@)

相关问答

依赖报错 idea导入项目后依赖报错,解决方案:https://blog....
错误1:代码生成器依赖和mybatis依赖冲突 启动项目时报错如下...
错误1:gradle项目控制台输出为乱码 # 解决方案:https://bl...
错误还原:在查询的过程中,传入的workType为0时,该条件不起...
报错如下,gcc版本太低 ^ server.c:5346:31: 错误:‘struct...