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[英]React TypeScript: Alternatives to UseRef in functional components
[英]React - useRef with TypeScript and functional component
我試圖從父組件調用子組件方法,我試圖使用 useRef。 將來,SayHi 方法將更新子組件中的鈎子狀態。 不幸的是,我有無法處理的錯誤。
行: ref.current.SayHi();
類型“ForwardRefExoticComponent<{ name: string;”上不存在屬性“SayHi” } & RefAttributes<{ SayHi: () => void; }>>'。
行: < Child name="Adam" ref={ref}/>
輸入'RefObject void; }>>>' 不能分配給類型 '((instance: { SayHi: () => void; } | null) => void) | RefObject<{ SayHi: () => void; }> | 空| 不明確的'。 輸入'RefObject void; }>>>' 不能分配給類型 'RefObject<{ SayHi: () => void; }>'。 “ForwardRefExoticComponent<{ name: string;”類型中缺少“SayHi”屬性 } & RefAttributes<{ SayHi: () => void; }>>' 但在類型 '{ SayHi: () => void; 中是必需的; }'。
完整的 test.tsx 文件:
import React, { useRef, forwardRef, useImperativeHandle, Ref } from 'react'
const Parent = () => {
const ref = useRef<typeof Child>(null);
const onButtonClick = () => {
if (ref.current) {
ref.current.SayHi();
}
};
return (
<div>
<Child name="Adam" ref={ref}/>
<button onClick={onButtonClick}>Log console</button>
</div>
);
}
const Child = forwardRef((props: {name: string}, ref: Ref<{SayHi: () => void}>)=> {
const {name} = props;
useImperativeHandle(ref, () => ({ SayHi }));
function SayHi() { console.log("Hello " + name); }
return <div>{name}</div>;
});
我深切地尋求有關此主題的幫助。
您需要在別處提取 ref 類型:
interface RefObject {
SayHi: () => void
}
然后在兩個地方都引用它
const Child = forwardRef((props: {name: string}, ref: Ref<RefObject>)=> {
const {name} = props;
useImperativeHandle(ref, () => ({ SayHi }));
function SayHi() { console.log("Hello " + name); }
return <div>{name}</div>;
});
const Parent = () => {
const ref = useRef<RefObject>(null);
const onButtonClick = () => {
if (ref.current) {
ref.current.SayHi();
}
};
return (
<div>
<Child name="Adam" ref={ref}/>
<button onClick={onButtonClick}>Log console</button>
</div>
);
}
只需用這個const ref = useRef<{ SayHi: () => void }>(null);
替換你的ref
的聲明const ref = useRef<{ SayHi: () => void }>(null);
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