{"id":6193,"date":"2022-06-21T15:06:15","date_gmt":"2022-06-21T07:06:15","guid":{"rendered":"https:\/\/www.lilichao.com\/?p=6193"},"modified":"2022-06-22T11:17:53","modified_gmt":"2022-06-22T03:17:53","slug":"%e5%85%b3%e4%ba%8ehook","status":"publish","type":"post","link":"https:\/\/lilichao.com\/?p=6193","title":{"rendered":"\u5173\u4e8eHook"},"content":{"rendered":"\n<p>\u5173\u4e8eReact\u4e2d\u7684\u94a9\u5b50\u51fd\u6570\uff0c\u6211\u4eec\u5df2\u7ecf\u975e\u5e38\u719f\u6089\u4e86\u3002\u94a9\u5b50\u51fd\u6570\u7684\u529f\u80fd\u975e\u5e38\u7684\u5f3a\u5927\uff0c\u800c\u5b83\u7684\u4f7f\u7528\u53c8\u5341\u5206\u7b80\u5355\u3002\u5173\u4e8e\u94a9\u5b50\u51fd\u6570\u7684\u4f7f\u7528\uff0c\u6211\u4eec\u53ea\u9700\u8bb0\u4f4f\u4e24\u70b9\uff1a<\/p>\n\n\n\n<ol><li>\u94a9\u5b50\u53ea\u80fd\u5728React\u7ec4\u4ef6\u548c\u81ea\u5b9a\u4e49\u94a9\u5b50\u4e2d\u4f7f\u7528<\/li><li>\u94a9\u5b50\u4e0d\u80fd\u5728\u5d4c\u5957\u51fd\u6570\u6216\u5176\u4ed6\u8bed\u53e5\uff08if\u3001switch\u3001white\u3001for\u7b49\uff09\u4e2d\u4f7f\u7528<\/li><\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">React\u4e2d\u81ea\u5e26\u7684\u94a9\u5b50\u51fd\u6570<\/h2>\n\n\n\n<ol><li>useState<\/li><li>useEffect<\/li><li>useContext<\/li><li>useReducer<\/li><li>useCallback<\/li><li>useRef<\/li><li>useMemo<\/li><li>useImperativeHandle<\/li><li>useLayoutEffect<\/li><li>useDebugValue\uff0818.0\u65b0\u589e\uff09<\/li><li>useDeferredValue\uff0818.0\u65b0\u589e\uff09<\/li><li>useTransition\uff0818.0\u65b0\u589e\uff09<\/li><li>useId\uff0818.0\u65b0\u589e\uff09<\/li><li>useSyncExternalStore\uff0818.0\u65b0\u589e\uff09<\/li><li>useInsertionEffect\uff0818.0\u65b0\u589e\uff09<\/li><\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">useMemo<\/h2>\n\n\n\n<p>useMemo\u548cuseCallback\u5341\u5206\u76f8\u4f3c\uff0cuseCallback\u7528\u6765\u7f13\u5b58\u51fd\u6570\u5bf9\u8c61\uff0cuseMemo\u7528\u6765\u7f13\u5b58\u51fd\u6570\u7684\u6267\u884c\u7ed3\u679c\u3002\u5728\u7ec4\u4ef6\u4e2d\uff0c\u4f1a\u6709\u4e00\u4e9b\u51fd\u6570\u5177\u6709\u5341\u5206\u7684\u590d\u6742\u7684\u903b\u8f91\uff0c\u6267\u884c\u901f\u5ea6\u6bd4\u8f83\u6162\u3002\u95ed\u4e86\u907f\u514d\u8fd9\u4e9b\u6267\u884c\u901f\u5ea6\u6162\u7684\u51fd\u6570\u8fd4\u56de\u6267\u884c\uff0c\u53ef\u4ee5\u901a\u8fc7useMemo\u6765\u7f13\u5b58\u5b83\u4eec\u7684\u6267\u884c\u7ed3\u679c\uff0c\u50cf\u662f\u8fd9\u6837\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">const result = <em>useMemo<\/em>(()=&gt;{\n    return \u590d\u6742\u903b\u8f91\u51fd\u6570();\n},[\u4f9d\u8d56\u9879])<\/pre>\n\n\n\n<p>useMemo\u4e2d\u7684\u51fd\u6570\u4f1a\u5728\u4f9d\u8d56\u9879\u53d1\u751f\u53d8\u5316\u65f6\u6267\u884c\uff0c\u6ce8\u610f\uff01\u662f\u6267\u884c\uff0c\u8fd9\u70b9\u548cuseCallback\u4e0d\u540c\uff0cuseCallback\u662f\u521b\u5efa\u3002\u6267\u884c\u540e\u8fd4\u56de\u6267\u884c\u7ed3\u679c\uff0c\u5982\u679c\u4f9d\u8d56\u9879\u4e0d\u53d1\u751f\u53d8\u5316\uff0c\u5219\u4e00\u76f4\u4f1a\u8fd4\u56de\u4e0a\u6b21\u7684\u7ed3\u679c\uff0c\u4e0d\u4f1a\u518d\u6267\u884c\u51fd\u6570\u3002\u8fd9\u6837\u4e00\u6765\u5c31\u907f\u514d\u590d\u6742\u903b\u8f91\u7684\u91cd\u590d\u6267\u884c\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">useImperativeHandle<\/h2>\n\n\n\n<p>\u5728React\u4e2d\u53ef\u4ee5\u901a\u8fc7forwardRef\u6765\u6307\u5b9a\u8981\u66b4\u9732\u7ed9\u5916\u90e8\u7ec4\u4ef6\u7684ref\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">const MyButton = <em>forwardRef<\/em>((props, ref) =&gt; {<br>    return &lt;button ref={ref}&gt;\u81ea\u5b9a\u4e49\u6309\u94ae&lt;\/button&gt;<br>});<\/pre>\n\n\n\n<p>\u4e0a\u4f8b\u4e2d\uff0cMyButton\u7ec4\u4ef6\u5c06button\u7684ref\u4f5c\u4e3a\u7ec4\u4ef6\u7684ref\u5411\u5916\u90e8\u66b4\u9732\uff0c\u5176\u4ed6\u7ec4\u4ef6\u5728\u4f7f\u7528MyButton\u65f6\uff0c\u5c31\u53ef\u4ee5\u901a\u8fc7ref\u5c5e\u6027\u8bbf\u95ee\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;MyButton ref={btnRef}\/&gt;<\/pre>\n\n\n\n<p>\u901a\u8fc7useImperativeHandle\u53ef\u4ee5\u624b\u52a8\u7684\u6307\u5b9aref\u8981\u66b4\u9732\u7684\u5bf9\u8c61\uff0c\u6bd4\u5982\u53ef\u4ee5\u4fee\u6539MyButton\u7ec4\u4ef6\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">const MyButton = <em>forwardRef<\/em>((props, ref) =&gt; {<br><br>    <em>useImperativeHandle<\/em>(ref,()=&gt; {<br>        return {<br>            name:'\u5b59\u609f\u7a7a'<br>        };<br>    });<br><br>    return &lt;button&gt;\u81ea\u5b9a\u4e49\u6309\u94ae&lt;\/button&gt;<br>});<\/pre>\n\n\n\n<p>useImperativeHandle\u7684\u7b2c\u4e8c\u4e2a\u53c2\u6570\u662f\u4e00\u4e2a\u51fd\u6570\uff0c\u51fd\u6570\u7684\u8fd4\u56de\u503c\u4f1a\u81ea\u52a8\u8d4b\u503c\u7ed9ref\uff08current\u5c5e\u6027\uff09\u3002\u4e0a\u4f8b\u4e2d\uff0c\u6211\u4eec\u5c06\u8fd4\u56de\u503c\u4e3a<code>{name:'\u5b59\u609f\u7a7a'}<\/code>\uff0c\u5f53\u7136\u8fd4\u56de\u5b59\u609f\u7a7a\u6ca1\u6709\u4ec0\u4e48\u610f\u4e49\u3002\u5b9e\u9645\u5f00\u53d1\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u4e00\u4e9b\u64cd\u4f5c\u65b9\u6cd5\u5b9a\u4e49\u5230\u5bf9\u8c61\u4e2d\uff0c\u8fd9\u6837\u53ef\u4ee5\u6709\u6548\u7684\u51cf\u5c11\u7ec4\u4ef6\u5bf9DOM\u5bf9\u8c61\u7684\u76f4\u63a5\u64cd\u4f5c\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">const MyButton = <em>forwardRef<\/em>((props, ref) =&gt; {\n\n    const btnRef = <em>useRef<\/em>();\n\n    <em>useImperativeHandle<\/em>(ref,()=&gt; {\n        return {\n            setDisabled(){\n                btnRef.current.disabled = true;\n            }\n        };\n    });\n\n    return &lt;button ref={btnRef}&gt;\u81ea\u5b9a\u4e49\u6309\u94ae&lt;\/button&gt;\n});\n\nconst App = () =&gt; {\n    \n    const btnRef = useRef();\n\n    const clickHandler = () =&gt; {\n        btnRef.current.setDisabled();\n    };\n\n    return &lt;div&gt;\n        &lt;MyButton ref={btnRef}\/&gt;\n        &lt;button onClick={clickHandler}&gt;\u70b9\u51fb&lt;\/button&gt;\n    &lt;\/div&gt;;\n};<\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">useLayoutEffect<\/h2>\n\n\n\n<p>useLayoutEffect\u7684\u65b9\u6cd5\u7b7e\u540d\u548cuseEffect\u4e00\u6837\uff0c\u529f\u80fd\u4e5f\u7c7b\u4f3c\u3002\u4e0d\u540c\u70b9\u5728\u4e8e\uff0cuseLayoutEffect\u7684\u6267\u884c\u65f6\u673a\u8981\u65e9\u4e8euseEffect\uff0c\u5b83\u4f1a\u5728DOM\u6539\u53d8\u540e\u8c03\u7528\u3002\u5728\u8001\u7248\u672c\u7684React\u4e2d\u5b83\u548cuseEffect\u7684\u533a\u522b\u6bd4\u8f83\u597d\u6f14\u793a\uff0cReact18\u4e2d\uff0cuseEffect\u7684\u8fd0\u884c\u65b9\u5f0f\u6709\u6240\u53d8\u5316\uff0c\u6240\u4ee5\u4e8c\u8005\u533a\u522b\u4e0d\u597d\u6f14\u793a\u3002<\/p>\n\n\n\n<p>useLayoutEffect\u4f7f\u7528\u573a\u666f\u4e0d\u591a\uff0c\u5b9e\u9645\u5f00\u53d1\u4e2d\uff0c\u5728effect\u4e2d\u9700\u8981\u4fee\u6539\u5143\u7d20\u6837\u5f0f\uff0c\u4e14\u4f7f\u7528useEffect\u4f1a\u51fa\u73b0\u95ea\u70c1\u73b0\u8c61\u65f6\u53ef\u4ee5\u4f7f\u7528useLayoutEffect\u8fdb\u884c\u66ff\u6362\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"811\" height=\"646\" src=\"https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/06\/20220622111732278.png\" alt=\"\" class=\"wp-image-6253\" srcset=\"https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/06\/20220622111732278.png 811w, https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/06\/20220622111732278-300x239.png 300w, https:\/\/my-wp.oss-cn-beijing.aliyuncs.com\/wp-content\/uploads\/2022\/06\/20220622111732278-768x612.png 768w\" sizes=\"(max-width: 811px) 100vw, 811px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">useDebugValue<\/h2>\n\n\n\n<p>\u7528\u6765\u7ed9\u81ea\u5b9a\u4e49\u94a9\u5b50\u8bbe\u7f6e\u6807\u7b7e\uff0c\u6807\u7b7e\u4f1a\u5728React\u5f00\u53d1\u5de5\u5177\u4e2d\u663e\u793a\uff0c\u7528\u6765\u8c03\u8bd5\u81ea\u5b9a\u4e49\u94a9\u5b50\uff0c\u4e0d\u5e38\u7528\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">useDeferredValue<\/h2>\n\n\n\n<p>useDeferredValue\u7528\u6765\u8bbe\u7f6e\u4e00\u4e2a\u5ef6\u8fdf\u7684state\uff0c\u6bd4\u5982\u6211\u4eec\u521b\u5efa\u4e00\u4e2astate\uff0c\u5e76\u4f7f\u7528useDeferredValue\u83b7\u53d6\u5ef6\u8fdf\u503c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">const [queryStr, setQueryStr] = <em>useState<\/em>('');<br>const deferredQueryStr = <em>useDeferredValue<\/em>(queryStr);<\/pre>\n\n\n\n<p>\u4e0a\u8fb9\u7684\u4ee3\u7801\u4e2dqueryStr\u5c31\u662f\u4e00\u4e2a\u5e38\u89c4\u7684state\uff0cdeferredQueryStr\u5c31\u662fqueryStr\u7684\u5ef6\u8fdf\u503c\u3002\u8bbe\u7f6e\u5ef6\u8fdf\u503c\u540e\u6bcf\u6b21\u8c03\u7528setState\u540e\u90fd\u4f1a\u89e6\u53d1\u4e24\u6b21\u7ec4\u4ef6\u7684\u91cd\u65b0\u6e32\u67d3\u3002\u7b2c\u4e00\u6b21\u65f6\uff0cdeferredQueryStr\u7684\u503c\u662fqueryStr\u4fee\u6539\u524d\u7684\u503c\uff0c\u7b2c\u4e8c\u6b21\u624d\u662f\u4fee\u6539\u540e\u7684\u503c\u3002\u6362\u53e5\u8bdd\uff0c\u5ef6\u8fdf\u503c\u76f8\u8f83\u4e8estate\u6765\u8bf4\u603b\u4f1a\u6162\u4e00\u6b65\u66f4\u65b0\u3002<\/p>\n\n\n\n<p>\u5ef6\u8fdf\u503c\u53ef\u4ee5\u7528\u5728\u8fd9\u6837\u4e00\u4e2a\u573a\u666f\uff0c\u4e00\u4e2astate\u9700\u8981\u5728\u591a\u4e2a\u7ec4\u4ef6\u4e2d\u4f7f\u7528\u3002\u4e00\u4e2a\u7ec4\u4ef6\u7684\u6e32\u67d3\u6bd4\u8f83\u5feb\uff0c\u800c\u53e6\u4e00\u4e2a\u7ec4\u4ef6\u7684\u6e32\u67d3\u6bd4\u8f83\u6162\u3002\u8fd9\u6837\u6211\u4eec\u53ef\u4ee5\u4e3a\u8be5state\u521b\u5efa\u4e00\u4e2a\u5ef6\u8fdf\u503c\uff0c\u6e32\u67d3\u5feb\u7684\u7ec4\u4ef6\u4f7f\u7528\u6b63\u5e38\u7684state\u4f18\u5148\u663e\u793a\u3002\u6e32\u67d3\u6162\u7684\u7ec4\u4ef6\u4f7f\u7528\u5ef6\u8fdf\u503c\uff0c\u6162\u4e00\u6b65\u6e32\u67d3\u3002\u5f53\u7136\u5fc5\u987b\u7ed3\u5408React.memo\u6216useMemo\u624d\u80fd\u771f\u6b63\u7684\u53d1\u6325\u51fa\u5b83\u7684\u4f5c\u7528\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">useTransition<\/h2>\n\n\n\n<p>\u5f53\u6211\u4eec\u5728\u7ec4\u4ef6\u4e2d\u4fee\u6539state\u65f6\uff0c\u4f1a\u9047\u5230\u590d\u6742\u4e00\u4e9b\u7684state\uff0c\u5f53\u4fee\u6539\u8fd9\u4e9bstate\u65f6\uff0c\u751a\u81f3\u4f1a\u963b\u585e\u5230\u6574\u4e2a\u5e94\u7528\u7684\u8fd0\u884c\uff0c\u4e3a\u4e86\u964d\u4f4e\u8fd9\u79cdstate\u7684\u5f71\u54cd\uff0cReact\u4e3a\u6211\u4eec\u63d0\u4f9b\u4e86useTransition\uff0c\u901a\u8fc7useTransition\u53ef\u4ee5\u964d\u4f4esetState\u7684\u4f18\u5148\u7ea7\u3002<\/p>\n\n\n\n<p>useTransition\u4f1a\u8fd4\u56de\u4e00\u4e2a\u6570\u7ec4\uff0c\u6570\u7ec4\u4e2d\u6709\u4e24\u4e2a\u5143\u7d20\uff0c\u7b2c\u4e00\u4e2a\u5143\u7d20\u662fisPending\uff0c\u5b83\u662f\u4e00\u4e2a\u53d8\u91cf\u7528\u6765\u8bb0\u5f55transition\u662f\u5426\u5728\u6267\u884c\u4e2d\u3002\u7b2c\u4e8c\u4e2a\u5143\u7d20\u662fstartTransition\uff0c\u5b83\u662f\u4e00\u4e2a\u51fd\u6570\uff0c\u53ef\u4ee5\u5c06setState\u5728\u5176\u56de\u8c03\u51fd\u6570\u4e2d\u8c03\u7528\uff0c\u8fd9\u6837setState\u65b9\u6cd5\u4f1a\u88ab\u6807\u8bb0\u4e3atransition\u5e76\u4e0d\u4f1a\u7acb\u5373\u6267\u884c\uff0c\u800c\u662f\u5728\u5176\u4ed6\u4f18\u5148\u7ea7\u66f4\u9ad8\u7684\u65b9\u6cd5\u6267\u884c\u5b8c\u6bd5\uff0c\u624d\u4f1a\u6267\u884c\u3002<\/p>\n\n\n\n<p>\u9664\u4e86useTransition\u5916\uff0cReact\u8fd8\u76f4\u63a5\u4e3a\u4e3a\u6211\u4eec\u63d0\u4f9b\u4e86\u4e00\u4e2astartTransition\u51fd\u6570\uff0c\u5728\u4e0d\u9700\u8981\u4f7f\u7528isPending\u65f6\uff0c\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528startTransition\u4e5f\u53ef\u4ee5\u8fbe\u5230\u76f8\u540c\u7684\u6548\u679c\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">useId<\/h2>\n\n\n\n<p>\u751f\u6210\u552f\u4e00id\uff0c\u4f7f\u7528\u4e8e\u9700\u8981\u552f\u4e00id\u7684\u573a\u666f\uff0c\u4f46\u4e0d\u9002\u7528\u4e8e\u5217\u8868\u7684key\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5173\u4e8eReact\u4e2d\u7684\u94a9\u5b50\u51fd\u6570\uff0c\u6211\u4eec\u5df2\u7ecf\u975e\u5e38\u719f\u6089\u4e86\u3002\u94a9\u5b50\u51fd\u6570\u7684\u529f\u80fd\u975e\u5e38\u7684\u5f3a\u5927\uff0c\u800c\u5b83\u7684\u4f7f\u7528\u53c8\u5341\u5206\u7b80\u5355\u3002\u5173\u4e8e\u94a9\u5b50\u51fd\u6570\u7684 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6147,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[198],"tags":[262,200,202],"_links":{"self":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6193"}],"collection":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6193"}],"version-history":[{"count":5,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6193\/revisions"}],"predecessor-version":[{"id":6254,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/posts\/6193\/revisions\/6254"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=\/wp\/v2\/media\/6147"}],"wp:attachment":[{"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6193"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6193"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lilichao.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6193"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}