废话不多说,直接上代码。
代码如下:
1、封装一个公共文件createContext.js
在src/utils文件夹下新建一个createContext.js文件,代码如下:
// createContext.js文件
import { createContext } from "react";
const myContext = createContext(null);
export default myContext;
2、在父组件中使用
import React, { useState} from "react";
import Count from './count'
import myContext from '@/utils/createContext'
function App() {
const [count, setCount] = useState(0);
return (
<div>
<h3>Father</h3>
<p>You clicked {count} times</p>
<button onClick={() => { setCount(count + 1) }}>
click me
</button>
<myContext.Provider value={count}>
<Count />
</myContext.Provider>
</div>
);
}
export default App;
3、创建子组件count.tsx:
import React, { useContext} from 'react';
import myContext from '@/utils/createContext'
function Count() {
const count = useContext(myContext); // 得到父组件传的值
return (
<div>
<h3>我是子组件</h3>
<p>这是父组件传过来的值:{count}</p>
</div>
)
}
export default Count;