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[英]Material UI IconButton onClick to increment or decrement values
[英]Conditional rendering in React based on the onClick property of the IconButton component in Material UI
import "./styles.css";
import React, { useState } from "react";
import { IconButton } from "@material-ui/core";
import ExpandMoreIcon from "@material-ui/icons/ExpandMore";
export default function App() {
const [expand, setExpand] = useState({
arrowA: false,
arrowB: false,
arrowC: false,
arrowD: false
});
const handleChange = (e) => {
setExpand({
...expand,
[e.currentTarget.name]: !expand.arrowA,
[e.currentTarget.name]: !expand.arrowB,
[e.currentTarget.name]: !expand.arrowC,
[e.currentTarget.name]: !expand.arrowD
});
};
return (
<div className="App">
<h1>React conditional rendering</h1>
<h2>
The component below should render if the user clicks on the arrow, and
be removed if the user clicks the arrow again.
</h2>
<h5>
This arrow should show the first part of the text.{" "}
<IconButton
variant="contained"
size="small"
color="primary"
aria-label="expand"
name="arrowA"
onClick={handleChange}
>
{<ExpandMoreIcon />}
</IconButton>
</h5>
<h5>
This arrow show the second part of the text if clicked, and be possible
to remove.
<IconButton
variant="contained"
size="small"
color="primary"
aria-label="expand"
name="arrowB"
onClick={handleChange}
>
{<ExpandMoreIcon />}
</IconButton>
</h5>
<h5>
This arrow should show the third part of the text below.{" "}
<IconButton
variant="contained"
size="small"
color="primary"
aria-label="expand"
name="arrowC"
onClick={handleChange}
>
{<ExpandMoreIcon />}
</IconButton>
</h5>
<h5>
This was really the last part.{" "}
<IconButton
variant="contained"
size="small"
color="primary"
aria-label="expand"
name="arrowD"
onClick={handleChange}
>
{<ExpandMoreIcon />}
</IconButton>
</h5>
{expand.arrowA ? (
<h2>
This is the first start of the story, let's see if we can add the
rest.
</h2>
) : null}
{expand.arrowB ? (
<h2>This is the middle part, it starts to break soon.</h2>
) : null}
{expand.arrowC ? (
<h2>
We are nearing the end. But as you see, this state management is not
optimal.
</h2>
) : null}
{expand.arrowD ? (
<h2>
This is was all I wanted to show. But why is removing this so hard?
How to make this better?
</h2>
) : null}
</div>
);
}
首先,感謝您來到這里。 我是 React 的初學者,並且有一個關於如何使我的 state 管理更優化和更好工作的問題。
我試圖在一個 React 鈎子中渲染多個組件,以避免創建許多不同的鈎子。 但是我的解決方案不能正常工作,也不是很理想。 我缺乏如何讓 state 更有活力的知識,但我覺得我很接近。 以下是示例:代碼沙箱
如果您打開代碼沙箱,在第二次嘗試文件中,我嘗試設置[e.currentTarget.value]: [e.currentTarget.status]
以嘗試從 IconButton 獲取狀態,我將其存儲為status={.expand.checkedA}
。 但這顯然不是 React state 管理的工作方式。
有人可以告訴我這里的最佳做法是什么嗎? 如果您對有條件地渲染多個組件的替代方法有建議,我也會很好奇。
干杯。
我認為您做得很好,我只需更改一些內容即可使其正常工作:
首先讓handleChange執行此操作,而不是當前代碼:
const handleChange = (e) => {
setExpand({
...expand,
[e.currentTarget.name]: !expand[e.currentTarget.name]
});
};
這樣,您只需更改您單擊的那個,rest 將保持不變。
其次,您的 jsx 中不需要三元運算符,您可以使用 && 運算符:
{expand.arrowA && (
<h2>
This is the first start of the story, let's see if we can add the
rest.
</h2>
)}
如果您有任何問題,請檢查分叉沙箱: https://codesandbox.io/s/cool-fog-h7vct?file=/src/App.js:2073-2226
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