所以我有一个数据数组,我正在生成一个包含该数据的组件列表。我想在每个生成的元素上有一个 ref 来计算高度。 我知道如何使用 Class 组件来完成,但我想使用 React Hooks 来完成。
这是一个解释我想做什么的例子:
import React, {useState, useCallback} from 'react'
const data = [
{
text: 'test1'
},
{
text: 'test2'
}
]
const Component = () => {
const [height, setHeight] = useState(0);
const measuredRef = useCallback(node => {
if (node !== null) {
setHeight(node.getBoundingClientRect().height);
}
}, []);
return (
<div>
{
data.map((item, index) =>
<div ref={measuredRef} key={index}>
{item.text}
</div>
)
}
</div>
)
}
最佳答案
不确定我是否完全理解您的意图,但我认为您想要这样的东西:
const {
useState,
useRef,
createRef,
useEffect
} = React;
const data = [
{
text: "test1"
},
{
text: "test2"
}
];
const Component = () => {
const [heights, setHeights] = useState([]);
const elementsRef = useRef(data.map(() => createRef()));
useEffect(() => {
const nextHeights = elementsRef.current.map(
ref => ref.current.getBoundingClientRect().height
);
setHeights(nextHeights);
}, []);
return (
<div>
{data.map((item, index) => (
<div ref={elementsRef.current[index]} key={index} className={`item item-${index}`}>
{`${item.text} - height(${heights[index]})`}
</div>
))}
</div>
);
};
const rootElement = document.getElementById("root");
ReactDOM.render(<Component />, rootElement);
.item {
box-sizing: border-box;
display: flex;
align-items: center;
justify-content: center;
border: 1px solid #ccc;
}
.item-0 {
height: 25px;
}
.item-1 {
height: 50px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.6/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.6/umd/react-dom.production.min.js"></script>
<div id="root"/>
关于javascript - 如何使用 react Hook 动态添加 "refs"?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/55995760/