Reactjs 这个状态钩子有什么问题?
我在网上找到了这个组件,它创建了一个评论组件,但它不工作Reactjs 这个状态钩子有什么问题?,reactjs,react-hooks,Reactjs,React Hooks,我在网上找到了这个组件,它创建了一个评论组件,但它不工作 import { useState } from 'react'; const Star = ({filled, starId}) => ( <span star-id={starId} style={{ color: '#ff9933' }} role="button"> {filled ? '\u2605' : '\u2606'} </span> ); export const Rating
import { useState } from 'react';
const Star = ({filled, starId}) => (
<span star-id={starId} style={{ color: '#ff9933' }} role="button">
{filled ? '\u2605' : '\u2606'}
</span>
);
export const Rating = props => (
const [rating, setRating] = useState(typeof props.rating == 'number' ? props.rating : 0);
const [selection, setSelection] = useState(0);
const hoverOver = event => {
let val = 0;
if (event && event.target && event.target.getAttribute('star-id'))
val = event.target.getAttribute('star-id');
setSelection(val);
};
return (
<div
onMouseOut={() => hoverOver(null)}
onClick={event => setRating(event.target.getAttribute('star-id') || rating)}
onMouseOver={hoverOver}
>
{Array.from({ length: 5 }, (v, i) => (
<Star
starId={i + 1}
key={`star_${i + 1} `}
filled={selection ? selection >= i + 1 : rating >= i + 1}
/>
))}
</div>
);
怎么了?如何修复它呢?我认为钩子很好,但是您需要在函数体周围使用
{}
:
export const Rating = props => {
const [rating, setRating] = useState((typeof props.rating === 'number') ? props.rating : 0);
const [selection, setSelection] = useState(0);
const hoverOver = event => {
let val = 0;
if (event && event.target && event.target.getAttribute('star-id'))
val = event.target.getAttribute('star-id');
setSelection(val);
};
return (
<div
onMouseOut={() => hoverOver(null)}
onClick={event => setRating(event.target.getAttribute('star-id') || rating)}
onMouseOver={hoverOver}
>
{Array.from({ length: 5 }, (v, i) => (
<Star
starId={i + 1}
key={`star_${i + 1} `}
filled={selection ? selection >= i + 1 : rating >= i + 1}
/>
))}
</div>
);
};
export const Rating=props=>{
const[rating,setRating]=useState((typeof props.rating==='number')?props.rating:0);
const[selection,setSelection]=useState(0);
常数悬停=事件=>{
设val=0;
if(event&&event.target&&event.target.getAttribute('star-id'))
val=event.target.getAttribute('star-id');
选举(val);
};
返回(
悬停(空)}
onClick={event=>setRating(event.target.getAttribute('star-id')| | rating)}
onMouseOver={hoverOver}
>
{Array.from({length:5},(v,i)=>(
=i+1:评级>=i+1}
/>
))}
);
};
您应该考虑的第二件事是:您可能应该使用
==
而不是=
来进行类型的检查。我认为钩子很好,但是您需要在函数体周围使用{}
:
export const Rating = props => {
const [rating, setRating] = useState((typeof props.rating === 'number') ? props.rating : 0);
const [selection, setSelection] = useState(0);
const hoverOver = event => {
let val = 0;
if (event && event.target && event.target.getAttribute('star-id'))
val = event.target.getAttribute('star-id');
setSelection(val);
};
return (
<div
onMouseOut={() => hoverOver(null)}
onClick={event => setRating(event.target.getAttribute('star-id') || rating)}
onMouseOver={hoverOver}
>
{Array.from({ length: 5 }, (v, i) => (
<Star
starId={i + 1}
key={`star_${i + 1} `}
filled={selection ? selection >= i + 1 : rating >= i + 1}
/>
))}
</div>
);
};
export const Rating=props=>{
const[rating,setRating]=useState((typeof props.rating==='number')?props.rating:0);
const[selection,setSelection]=useState(0);
常数悬停=事件=>{
设val=0;
if(event&&event.target&&event.target.getAttribute('star-id'))
val=event.target.getAttribute('star-id');
选举(val);
};
返回(
悬停(空)}
onClick={event=>setRating(event.target.getAttribute('star-id')| | rating)}
onMouseOver={hoverOver}
>
{Array.from({length:5},(v,i)=>(
=i+1:评级>=i+1}
/>
))}
);
};
您应该考虑的第二件事是:您可能应该使用==
而不是=
进行类型的检查。错误是什么?引发了什么错误?错误是什么?引发了什么错误?