react 祖孙关系传递

1. utils下的context.js

import React ,{ createContext} from "react" //createContext 是创建一个上下文对象
export const dateContext= createContext({}) // 创建了一个上下文对象
export const {Provider,Consumer} = dateContext

2.爷爷组件

import {Provider} from "../utils/context"
  <Provider value={obj}>
              <Appson sendfn={sendfn}></Appson>
     </Provider>

3.孙子组件

 import React from 'react'
import {useContext} from "react" // 
import {dateContext} from "../utils/context"
function Appgrand() {
   let contextValue = useContext(dateContext)
   console.log(contextValue,111);
  return (
    <div> 我是爷爷组件传递来的数据{contextValue.name}</div>
  )
}

export default Appgrand