龙岩市网站建设_网站建设公司_自助建站_seo优化

一、跨层级传递

import { useContext, createContext, useState } from "react"const msgContext = createContext()
function A(){const m = useContext(msgContext)return (<div>A-{m}<B></B></div>
  )
}
function B(){const m = useContext(msgContext)return (<div>B-{m}</div>
  )
}function App(){const message = 'my name is msg'return (<div><msgContext.Provider value={message}><A ></A></msgContext.Provider>  </div>
  )
}export default App