{"id":273,"date":"2025-08-13T05:55:17","date_gmt":"2025-08-13T05:55:17","guid":{"rendered":"https:\/\/www.yehger.com\/?p=273"},"modified":"2025-08-13T05:58:15","modified_gmt":"2025-08-13T05:58:15","slug":"react-usestate%e6%83%b0%e6%80%a7%e5%88%9d%e5%a7%8b%e5%8c%96%e5%87%bd%e6%95%b0%e4%bd%bf%e7%94%a8%e5%9c%ba%e6%99%af","status":"publish","type":"post","link":"https:\/\/www.yehger.com\/index.php\/2025\/08\/13\/react-usestate%e6%83%b0%e6%80%a7%e5%88%9d%e5%a7%8b%e5%8c%96%e5%87%bd%e6%95%b0%e4%bd%bf%e7%94%a8%e5%9c%ba%e6%99%af\/","title":{"rendered":"React useState\u60f0\u6027\u521d\u59cb\u5316\u51fd\u6570\u4f7f\u7528\u573a\u666f"},"content":{"rendered":"<h1>\u4e00\u3001\u4ece\u7f13\u5b58\u6216\u5916\u90e8\u73af\u5883\u4e2d\u6062\u590d\u72b6\u6001<\/h1>\n<p>\u573a\u666f\uff1a\u4ece localStorage\u3001sessionStorage\u3001cookie\u3001indexedDB\u3001URL \u53c2\u6570 \u7b49\u6765\u6e90\u8bfb\u53d6\u521d\u59cb\u503c\u3002<\/p>\n<pre><code class=\"language-tsx\">const [theme, setTheme] = useState(() =&gt; {\n  return localStorage.getItem(&#039;theme&#039;) || &#039;light&#039;;\n});<\/code><\/pre>\n<ul>\n<li>\u907f\u514d\u6bcf\u6b21\u6e32\u67d3\u90fd\u8bbf\u95ee\u5b58\u50a8\uff0c\u51cf\u5c11 I\/O\u3002<\/li>\n<\/ul>\n<hr \/>\n<h1>\u4e8c\u3001\u521d\u59cb\u5316\u5927\u578b\u6570\u636e\u7ed3\u6784<\/h1>\n<pre><code class=\"language-tsx\">const [graph, setGraph] = useState(() =&gt; {\n  return generateGraph(10000); \/\/ \u751f\u6210 1 \u4e07\u8282\u70b9\n});<\/code><\/pre>\n<ul>\n<li>\u4ec5\u9996\u6e32\u67d3\u751f\u6210\u4e00\u6b21\uff0c\u51cf\u5c11\u91cd\u590d\u8ba1\u7b97\u5f00\u9500\u3002<\/li>\n<\/ul>\n<hr \/>\n<h1>\u4e09\u3001\u4f9d\u8d56\u5916\u90e8\u73af\u5883\u53d8\u91cf\uff08Node.js\u3001\u5168\u5c40\u914d\u7f6e\u7b49\uff09<\/h1>\n<pre><code class=\"language-tsx\">const [apiBase] = useState(() =&gt; {\n  return process.env.NODE_ENV === &#039;production&#039; ? &#039;\/prod&#039; : &#039;\/dev&#039;;\n});<\/code><\/pre>\n<ul>\n<li>\u907f\u514d\u5728\u6bcf\u6b21\u6e32\u67d3\u90fd\u8bfb\u53d6\u5168\u5c40\u72b6\u6001\u3002<\/li>\n<\/ul>\n<hr \/>\n<h1>\u56db\u3001\u6839\u636e props \u8ba1\u7b97\u521d\u59cb\u72b6\u6001\uff08\u4f46\u540e\u7eed\u4e0d\u968f props \u6539\u53d8\uff09<\/h1>\n<p><strong>\u573a\u666f<\/strong>\uff1a\u53ea\u5728\u7b2c\u4e00\u6b21\u6839\u636e props \u6d3e\u751f state\u3002<\/p>\n<pre><code class=\"language-tsx\">function UserForm({ defaultName }) {\n  const [name, setName] = useState(() =&gt; defaultName.trim());\n  \/\/ defaultName \u540e\u7eed\u53d8\u5316\u4e0d\u4f1a\u5f71\u54cd state\n}<\/code><\/pre>\n<hr \/>\n<h1>\u4e94\u3001\u751f\u6210\u968f\u673a\u503c \/ \u552f\u4e00 ID \u521d\u59cb\u5316<\/h1>\n<pre><code class=\"language-tsx\">const [sessionId] = useState(() =&gt; crypto.randomUUID());<\/code><\/pre>\n<ul>\n<li>\u4fdd\u8bc1\u6e32\u67d3\u671f\u95f4\u8be5\u503c\u7a33\u5b9a\uff0c\u4e0d\u4f1a\u6bcf\u6b21\u90fd\u53d8\u3002<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u4e00\u3001\u4ece\u7f13\u5b58\u6216\u5916\u90e8\u73af\u5883\u4e2d\u6062\u590d\u72b6\u6001 \u573a\u666f\uff1a\u4ece localStorage\u3001sessionStorage\u3001cookie\u3001indexedDB\u3001URL \u53c2\u6570 \u7b49\u6765\u6e90\u8bfb\u53d6\u521d\u59cb\u503c\u3002 const [theme, setTheme] = useState(() =&gt; { return localStorage.getItem(&#039;theme&#039;) || &#039;light&#039;; }); \u907f\u514d\u6bcf\u6b21\u6e32\u67d3\u90fd\u8bbf\u95ee\u5b58\u50a8\uff0c\u51cf\u5c11 I\/O\u3002 \u4e8c\u3001\u521d\u59cb\u5316\u5927\u578b\u6570\u636e\u7ed3\u6784&#8230; <a class=\"read-more\" href=\"https:\/\/www.yehger.com\/index.php\/2025\/08\/13\/react-usestate%e6%83%b0%e6%80%a7%e5%88%9d%e5%a7%8b%e5%8c%96%e5%87%bd%e6%95%b0%e4%bd%bf%e7%94%a8%e5%9c%ba%e6%99%af\/\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-273","post","type-post","status-publish","format-standard","hentry","category-react-study"],"_links":{"self":[{"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/posts\/273","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/comments?post=273"}],"version-history":[{"count":4,"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/posts\/273\/revisions"}],"predecessor-version":[{"id":278,"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/posts\/273\/revisions\/278"}],"wp:attachment":[{"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/media?parent=273"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/categories?post=273"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.yehger.com\/index.php\/wp-json\/wp\/v2\/tags?post=273"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}