useMapContext在父组件中解构出来的map无法控制地图实例，hooks用法下useMapContext的用法能否烦请详细说明？

[despire1119]

useMapContext在父组件中解构出来的map无法控制地图实例，hooks用法下useMapContext的用法能否烦请详细说明？感谢！

[jaywcjlove]

@despire1119 这里有个示例

react-baidu-map/packages/map/README.md

Lines 99 to 167 in 0e2615b

	### useMapContext & Provider
	通过 React 的 Context 提供了一个`无需`为每层组件手动注入 ~~`map`~~，~~`container`~~ 和 ~~`BMap`~~ 三个属性 `props`，就能在组件树间进行传递。
	> 🚧 在 `v2.3.0+` 版本支持
	<!--rehype:style=border-left: 8px solid #ffe564;background-color: #ffe56440;padding: 12px 10px;-->
	```jsx mdx:preview
	import React from 'react';
	import { useState, useRef, useEffect } from 'react';
	import { Map, APILoader, useMap, Provider, useMapContext } from '@uiw/react-baidu-map';
	const Marker = () => {
	const { map } = useMapContext();
	const container = useRef(null);
	const { setContainer } = useMap({
	zoom: 3,
	widget: ['GeolocationControl', 'NavigationControl']
	});
	useEffect(() => {
	if (container.current) {
	setContainer(container.current);
	}
	}, [container.current]);
	useEffect(() => {
	if (map) {
	// 创建点标记
	const marker1 = new BMap.Marker(new BMap.Point(116.404, 39.925));
	const marker2 = new BMap.Marker(new BMap.Point(116.404, 39.915));
	const marker3 = new BMap.Marker(new BMap.Point(116.395, 39.935));
	const marker4 = new BMap.Marker(new BMap.Point(116.415, 39.931));
	// 在地图上添加点标记
	map.addOverlay(marker1);
	map.addOverlay(marker2);
	map.addOverlay(marker3);
	map.addOverlay(marker4);
	}
	}, [map]);
	return (
	<div ref={container} style={{ height: 300 }} />
	);
	}
	const Demo = () => {
	return (
	<div style={{ width: '100%', height: '300px', overflow: 'auto' }}>
	<APILoader akay="eYpCTECSntZmw0WyoQ7zFpCRR9cpgHFG">
	<Provider>
	<div>
	<Marker />
	</div>
	</Provider>
	</APILoader>
	</div>
	);
	}
	export default Demo;
	```
	```js
	import { useMapContext, Provider } from '@uiw/react-baidu-map';
	const { BMap, map, container, state, dispatch } = useMapContext();
	// => state.BMap
	// => state.map
	// => state.container
	```