Published: May 14, 2022
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LastMod: January 04, 2023
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311 words
not assignable to type LegacyRef<xxxxx> 🔗 useRef定义一个ref时，报不能推断类型
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import React , { useRef , RefObject } from 'react' ;
function Test ()
{
const node = useRef < HTMLElement > ( null );
if (
node &&
node . current &&
node . current . contains ()
){ console . log ( "current accessed" )}
return < div ref = { node } >< /div>
}
因为useRef是使用HTMLElement定义的泛型，所以说不能推断，改成ref所对应的标签泛型就可以了
Cannot assign to ‘current’ because it is a read-only property 🔗 当在react中使用useRef定义ref时，报这样的错误, 因为结果走到React.RefObject
useRef有这3种定义
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function useRef < T >( initialValue : T ) : MutableRefObject < T >;
function useRef < T >( initialValue : T | null ) : RefObject < T >;
function useRef < T = undefined >() : MutableRefObject < T | undefined >;
useRef初始值设为null useRef定义了一个初始的类型 1
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const elem = useRef < HTMLDivElement >( null );
type Test = typeof elem ; // Test = React.RefObject<HTMLDivElement>
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error expect@29.3.1: The engine "node" is incompatible with this module. Expected version "^14.15.0 || ^16.10.0 || >=18.0.0" . Got "17.5.0"
error Found incompatible module.
如果是使用yarn安装时加上yarn --ignore-engines
