【发布时间】:2020-08-15 19:07:24
【问题描述】:
我有一些 React 功能组件,我想分享一个状态。在此示例中,两个切换按钮将有条件地显示/隐藏搜索栏和导航栏。
--基于接受的答案的解决方案,位于底部--
我对@987654321@ 完全陌生,我一直在控制台中遇到以下错误:
Uncaught TypeError: setSearchbarToggle is not a function 这适用于两个按钮。
下面我有一个过滤的示例代码。这只是我在一个文件中使用状态的示例。在现实生活中,我会在多个功能组件中重用状态。
这是我的header.js
import React, { useState, useContext } from "react"
import "./header.sass"
import { Context } from "./HeaderContext"
export const Header = () => {
const headerContext = useContext(Context)
const { navbarToggle, setNavbarToggle, searchbarToggle, setSearchbarToggle } = headerContext
return (
<React.Fragment>
<div className={"sticky-top"}>
<button onClick={ () => setNavbarToggle( !navbarToggle )}> Toggle Menu </button>
<button onClick={ () => setSearchbarToggle( !searchbarToggle )}> Toggle Search </button>
{navbarToggle && <h3>Menu is showing</h3>}
{searchbarToggle && <h3>Searchbar is showing</h3>}
</div>
</React.Fragment>
)
}
export default Header
这是我的HeaderContext.jsx
import React, { createContext, useState } from "react";
import PropTypes from "prop-types";
export const Context = createContext({});
export const Provider = props => {
const {
navbarToggle: initialNavBarToggle,
searchbarToggle: initialSarchbarToggle,
children
} = props;
const [navbarToggle, setNavbarToggle] = useState(initialNavBarToggle);
const [searchbarToggle, setSearchbarToggle] = useState(initialSarchbarToggle);
const headerContext = {
navbarToggle, setNavbarToggle,
searchbarToggle, setSearchbarToggle
};
return <Context.Provider value={headerContext}>{children}</Context.Provider>;
};
export const { Consumer } = Context;
Provider.propTypes = {
navbarToggle: PropTypes.bool,
searchbarToggle: PropTypes.bool
};
Provider.defaultProps = {
navbarToggle: false,
searchbarToggle: false
};
希望你能给我一些启示
--编辑--
这是我基于接受的答案的代码。
import React, { useContext } from "react"
import { Provider,Context } from "./HeaderContext"
export const HeaderWithContext= () => {
const headerContext = useContext(Context)
const { navbarToggle, setNavbarToggle, searchbarToggle, setSearchbarToggle } = headerContext
return (
<React.Fragment>
<div className={"sticky-top"}>
<button onClick={ () => setNavbarToggle( !navbarToggle )}> Toggle Menu </button>
<button onClick={ () => setSearchbarToggle( !searchbarToggle )}> Toggle Search </button>
{navbarToggle && <h3>Menu is showing</h3>}
{searchbarToggle && <h3>Searchbar is showing</h3>}
</div>
</React.Fragment>
)
}
export const Header = () => {
return (
<Provider>
<HeaderWithContext/>
</Provider>
)
};
【问题讨论】:
-
父组件之一,例如应用程序,必须
import { Provider } from "./HeaderContext"并用<Provider><Header /></Provider>包装标题(或其祖先组件之一)...你这样做了吗? -
@Aprillion,不,我没有。让我检查一下。我马上回来
-
哦,这比预期的要快。它就像你解释的那样工作。您能否将此作为答案,以便我接受? :) 另外,你知道我在哪里可以找到更好的读物吗?
-
我在答案中添加了一个文档链接 - 同一页面上有示例;)
标签: reactjs react-native react-hooks react-state