我在将状态从孩子发送到家长方面遇到了问题。点击主组件中的菜单后,我想改变状态active并将此active发送到侧边栏组件,因为我想隐藏/显示侧边栏取决于CSS中的active类。在Vanilla JS中很容易,但在React中我有点困惑。
主:
import Menu from "./Menu";
import "./Styles.css";
import teamsdb from "./teamsdb";
const Main = ({ name }) => {
return (
<div>
<Menu />
<h1>Main</h1>
<h4>{teamName}</h4>
</div>
);
};
菜单:
const Menu = () => {
const [active, setActive] = useState(false);
const changeMenu = () => {
setActive(!active);
};
return <button onClick={changeMenu}>Menu</button>;
};
export default Menu;
侧栏:
const Sidebar = () => {
const [searchTerm, setSearchTerm] = React.useState("");
const handleChange = e => {
setSearchTerm(e.target.value);
console.log("Search: ", e.target.value);
};
return (
<div className={active ? 'sidebar active' : 'sidebar'}>
<div className="sidebar__header">
Header
<button>Colors</button>
</div>
<div className="sidebar__search">
<input
type="text"
placeholder="Search"
value={searchTerm}
onChange={handleChange}
/>
</div>
<Teams search={searchTerm} />
</div>
);
};
应用程序JS
import React from "react";
import "./App.css";
import Sidebar from "./components/Sidebar";
import Main from "./components/Main";
import { BrowserRouter as Router, Switch, Route } from "react-router-dom";
function App() {
return (
<div className="App">
<div className="app__body">
<Router>
<Sidebar />
<Switch>
<Route path="/team/:teamId">
<Main />
</Route>
<Route exact path="/">
<Main />
</Route>
</Switch>
</Router>
</div>
</div>
);
}
您应该将状态提升到第一个公共祖先组件,在您的例子中是:app。通过传递状态和突变函数(setActive)作为prop,您可以在其所有后代中使用它:
App // Put active state here, pass down active and setActive as prop
^
|
+----+-----+
| |
+ +
Sidebar Main // Pass down active and setActive as prop
^
|
|
Menu // Use setActive to modify state in App
React文档中对此进行了解释:https://reactjs.org/docs/lifting-state-up.html