The first time you are trying to access ctx.current , it's still undefined because the assignment inside this effect still didn't happen: ... <看更多>

useRef.current is undefined even in useEffect hook #1190 ... No one assigned ... useRef(null); const navigationRef = React. ... <看更多>

const ethRef = useRef<Web3>(null);. In a useEffect which runs only when the component is mounted updated the ethRef reference with something ... ... <看更多>

Gatsby/SSR: window is not defined when building. ... import React, { useEffect, useCallback, useRef, Suspense } from 'react' // import style manually import ... ... <看更多>

The <Tooltip> and <Popover> components do not position themselves. ... For more advanced behaviors <OverlayTrigger> accepts a function child that passes in ... ... <看更多>

Learn how to use the useRef hook in React.Code: https://github.com/benawad/react-hooks-tutorial/tree ... ... <看更多>