每当程序注意到该主题时,我都会尝试使用 setState 更改值 currentTheme,该主题是存储在 App.js 中的状态更改为特定值。我收到此错误:
Error: Too many re-renders. React limits the number of renders to prevent an infinite loop.
不太确定在这里做什么,任何帮助将不胜感激。提前致谢!
import React, { useState } from "react";
import styled from "styled-components";
import Editor from "./Editor";
import { monokai, solarizedDark, terminal, textmate } from "./ui/themes";
const CodeContainer = ({ setHtml, setCss, setJs, setRenderDoc, theme }) => {
const [currentTheme, setCurrentTheme] = useState(monokai);
if (theme === "textmate") {
setCurrentTheme(textmate);
} else if (theme === "solarized_dark") {
setCurrentTheme(solarizedDark);
} else if (theme === "terminal") {
setCurrentTheme(terminal);
} else {
setCurrentTheme(monokai);
}
return (
<Container style={currentTheme}>
<Editor
setHtml={setHtml}
setRenderDoc={setRenderDoc}
languageName="html"
theme={theme}
/>
<Editor
setCss={setCss}
setRenderDoc={setRenderDoc}
languageName="css"
theme={theme}
/>
<Editor
setJs={setJs}
setRenderDoc={setRenderDoc}
languageName="javascript"
theme={theme}
/>
</Container>
);
};
export default CodeContainer;
const Container = styled.div`
height: 40vh;
border-bottom: 4px #211e1c solid;
display: flex;
align-items: center;
justify-content: space-between;
padding: 12px 15px;
`;
答案 0 :(得分:2)
我不认为你需要一个状态。做一个这样的函数,如果主题改变,它会为你获取正确的currentTheme。
const getTheme = (theme) => {
if (theme === "textmate")
return textmate;
if (theme === "solarized_dark")
return solarizedDark;
if (theme === "terminal")
return terminal;
return monokai;
}
这样称呼它:
<Container style={getTheme(theme)}>
或者,您可以使用局部变量内联计算主题:
const CodeContainer = ({ setHtml, setCss, setJs, setRenderDoc, theme }) => {
let currentTheme = monokai;
if (theme === "textmate") {
currentTheme = textmate;
} else if (theme === "solarized_dark") {
currentTheme = solarizedDark;
} else if (theme === "terminal") {
currentTheme = terminal;
}
return (
<Container style={currentTheme}>
//...
)
}
答案 1 :(得分:1)
正如评论中提到的,问题是您在每次渲染时都运行它,并且反应会注意到并阻止应用程序运行。
您可以利用 useEffect 钩子,它是一个用于监听值变化并根据这些变化产生副作用的钩子,它取代了基于类的组件中的所有生命周期方法。
React.useEffect(() => {
if (theme === "textmate") {
setCurrentTheme(textmate);
} else if (theme === "solarized_dark") {
setCurrentTheme(solarizedDark);
} else if (theme === "terminal") {
setCurrentTheme(terminal);
} else {
setCurrentTheme(monokai);
}
}, [theme])
第一个参数是一个回调,当主题值改变时,它会运行你想做的任何逻辑,第二个参数是一个数组,用于告诉 useEffect 何时运行,所以在这种情况下我们传递主题道具,它会告诉钩子在每次值改变时运行。 如果您想了解更多可以做的事情,这是它的文档: https://reactjs.org/docs/hooks-effect.html