{"id":336,"date":"2026-07-10T08:47:48","date_gmt":"2026-07-10T00:47:48","guid":{"rendered":"https:\/\/numsimlab.com\/?p=336"},"modified":"2026-07-10T08:47:48","modified_gmt":"2026-07-10T00:47:48","slug":"di%e4%be%9d%e8%b5%96%e6%b3%a8%e5%85%a5%e5%ae%b9%e5%99%a8%e9%9b%b6%e5%9f%ba%e7%a1%80%e5%ae%8c%e6%95%b4%e6%95%99%e7%a8%8b","status":"publish","type":"post","link":"https:\/\/numsimlab.com\/?p=336","title":{"rendered":"DI\u4f9d\u8d56\u6ce8\u5165\u5bb9\u5668\u96f6\u57fa\u7840\u5b8c\u6574\u6559\u7a0b"},"content":{"rendered":"\n\n\nDI\u4f9d\u8d56\u6ce8\u5165\u5bb9\u5668\u96f6\u57fa\u7840\u5b8c\u6574\u6559\u7a0b<\/title>\n<style>\n\/* \u57fa\u7840\u5168\u5c40\u6837\u5f0f \u5b8c\u5168\u6cbf\u7528\u539f\u7248\u98ce\u683c\u53d8\u91cf *\/\n*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}\nhtml{scroll-behavior:smooth}\n:root{\n --bg:#f8f9fa;--bg2:#fff;--ink:#1a1a2e;--muted:#6c7086;--rule:#e2e4eb;\n --accent:#2563eb;--accent2:#16a34a;--accent3:#dc2626;--accent4:#d97706;--accent5:#7c3aed;\n --card-bg:#fff;--code-bg:#f1f3f5;\n --tag-g:#dcfce7;--tag-g-t:#166534;--tag-b:#dbeafe;--tag-b-t:#1e40af;\n --tag-r:#fee2e2;--tag-r-t:#991b1b;--tag-y:#fef9c3;--tag-y-t:#713f12;--tag-p:#f3e8ff;--tag-p-t:#581c87;\n --shadow:0 1px 3px rgba(0,0,.08);--radius:8px;--max-w:960px\n}\n[data-theme=\"dark\"]{\n --bg:#0b0b1a;--bg2:#16162a;--ink:#e2e4f0;--muted:#7f8396;--rule:#26263e;\n --accent:#60a5fa;--accent2:#4ade80;--accent3:#f87171;--accent4:#fbbf24;--accent5:#a78bfa;\n --card-bg:#16162a;--code-bg:#1e2436;\n --tag-g:#14532d;--tag-g-t:#bbf7d0;--tag-b:#1e3a5f;--tag-b-t:#bfdbfe;\n --tag-r:#7f1d1d;--tag-r-t:#fecaca;--tag-y:#713f12;--tag-y-t:#fef08a;\n --tag-p:#3b1f6e;--tag-p-t:#e9d5ff;\n --shadow:0 1px 3px rgba(0,0,.3)\n}\nbody{\n font-family:-apple-system,BlinkMacSystemFont,\"Segoe UI\",\"Noto Sans SC\",\"PingFang SC\",\"Microsoft YaHei\",sans-serif;\n background:var(--bg);color:var(--ink);line-height:1.7;font-size:15px;\n transition:background .3s,color .3s;\n}\n\/* \u9876\u90e8\u5bfc\u822a\u680f *\/\nheader{\n position:fixed;top:0;left:0;right:0;z-index:100;\n background:var(--bg2);border-bottom:1px solid var(--rule);\n backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);\n}\n.header-wrap{\n max-width:var(--max-w);margin:0 auto;\n display:flex;align-items:center;justify-content:space-between;\n padding:0 1.2rem;height:56px;\n}\n.logo{\n font-weight:700;font-size:.98rem;color:var(--accent);\n display:flex;align-items:center;gap:.5rem;\n}\n.header-ctrl{display:flex;gap:.6rem;align-items:center}\n.lang-switch{display:flex;border:1px solid var(--rule);border-radius:6px;overflow:hidden}\n.lang-switch button{\n border:none;background:transparent;color:var(--muted);\n padding:.3rem .7rem;font-size:.8rem;cursor:pointer;\n transition:.2s all;font-family:inherit;\n}\n.lang-switch button.active{background:var(--accent);color:#fff}\n.lang-switch button:hover:not(.active){background:var(--rule);color:var(--ink)}\n.theme-btn{\n width:34px;height:34px;border:1px solid var(--rule);\n background:transparent;border-radius:6px;color:var(--muted);\n cursor:pointer;font-size:1rem;display:flex;align-items:center;justify-content:center;\n}\n.theme-btn:hover{background:var(--rule);color:var(--ink)}\n\n\/* \u4e3b\u4f53\u5bb9\u5668 \u7eb5\u5411\u5355\u680f\u6838\u5fc3\u5e03\u5c40 *\/\nmain{max-width:var(--max-w);margin:0 auto;padding:80px 1.2rem 4rem}\n.lang-block{display:none}\n.lang-block.active{display:block}\n\n\/* \u6807\u9898\u3001\u6bb5\u843d\u57fa\u7840 *\/\n.hero{text-align:center;margin-bottom:2.5rem}\nh1{font-size:1.8rem;font-weight:800;margin-bottom:.4rem;letter-spacing:-.02em}\nh1 .desc-sub{display:block;font-size:.86rem;color:var(--muted);font-weight:400;margin-top:.3rem}\nh2{\n font-size:1.3rem;font-weight:700;margin:2.2rem 0 .9rem;\n padding-bottom:.4rem;border-bottom:2px solid var(--accent);\n}\nh3{font-size:1.05rem;font-weight:600;margin:1.4rem 0 .5rem;color:var(--accent)}\nh4{font-size:.96rem;font-weight:600;margin:.9rem 0 .3rem}\np{margin-bottom:.8rem}\na{color:var(--accent);text-decoration:none}\na:hover{text-decoration:underline}\n\n\/* \u6807\u7b7e\u7ec4\u4ef6 *\/\n.tag{\n display:inline-block;padding:.14rem .5rem;border-radius:4px;\n font-size:.73rem;font-weight:600;margin-right:.3rem;white-space:nowrap;\n}\n.tag-g{background:var(--tag-g);color:var(--tag-g-t)}\n.tag-b{background:var(--tag-b);color:var(--tag-b-t)}\n.tag-p{background:var(--tag-p);color:var(--tag-p-t)}\n.tag-y{background:var(--tag-y);color:var(--tag-y-t)}\n.tag-r{background:var(--tag-r);color:var(--tag-r-t)}\n\n\/* \u5361\u7247\u3001\u63d0\u793a\u6846 *\/\n.card{\n background:var(--card-bg);border:1px solid var(--rule);\n border-radius:var(--radius);padding:1.3rem;margin-bottom:1.2rem;\n box-shadow:var(--shadow);\n}\n.tip-box{\n background:var(--bg);border-left:4px solid var(--accent);\n padding:.9rem 1rem;margin:1rem 0;border-radius:0 var(--radius) var(--radius) 0;\n font-size:.88rem;\n}\n.tip-box.warn{border-left-color:var(--accent4)}\n.tip-box.danger{border-left-color:var(--accent3)}\n.tip-box strong{color:var(--accent)}\n\n\/* \u76ee\u5f55\u6a21\u5757 *\/\n.toc-box{\n background:var(--card-bg);border:1px solid var(--rule);\n border-radius:var(--radius);padding:1.2rem 1.4rem;margin-bottom:2.2rem;\n box-shadow:var(--shadow);\n}\n.toc-box h3{margin:0 0 .6rem;font-size:.9rem;text-transform:uppercase;color:var(--muted)}\n.toc-box ol{padding-left:1.3rem}\n.toc-box li{margin-bottom:.3rem;font-size:.88rem}\n.toc-box a{color:var(--ink)}\n.toc-box a:hover{color:var(--accent);text-decoration:none}\n\n\/* \u4ee3\u7801\u5757\u6837\u5f0f *\/\npre.code{\n background:var(--code-bg);padding:.9rem 1rem;border-radius:var(--radius);\n overflow-x:auto;font-family:\"SF Mono\",Consolas,\"Courier New\",monospace;\n font-size:.82rem;line-height:1.5;margin:.7rem 0;border:1px solid var(--rule);\n}\ncode.inline{\n background:var(--code-bg);padding:.13rem .4rem;border-radius:4px;\n font-family:monospace;font-size:.83rem;border:1px solid var(--rule);\n}\n.terminal{\n background:#1a1a2e;color:#a8e6cf;padding:.9rem 1rem;border-radius:var(--radius);\n font-family:monospace;font-size:.82rem;overflow-x:auto;margin:.7rem 0;\n border:1px solid #333;line-height:1.6;\n}\n[data-theme=\"dark\"] .terminal{background:#08081a}\n\n\/* \u5bf9\u6bd4\u53cc\u680f\u6a21\u5757\uff08\u4ec5\u5bbd\u5c4f\u751f\u6548\uff0c\u7a84\u5c4f\u81ea\u52a8\u53d8\u5355\u680f\uff09 *\/\n.compare-wrap{\n display:grid;grid-template-columns:1fr 1fr;gap:1rem;margin:1.2rem 0;\n}\n.compare-item{\n background:var(--card-bg);border:1px solid var(--rule);\n border-radius:var(--radius);padding:1rem;box-shadow:var(--shadow);\n}\n.compare-item.bad h4{color:var(--accent3)}\n.compare-item.good h4{color:var(--accent2)}\n\n\/* \u547d\u4ee4\u5361\u7247\u7f51\u683c *\/\n.cmd-grid{\n display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:.8rem;margin:1.2rem 0;\n}\n.cmd-card{\n background:var(--card-bg);border:1px solid var(--rule);\n border-radius:var(--radius);padding:.9rem;box-shadow:var(--shadow);\n}\n.cmd-card h4{margin:0 0 .4rem;font-size:.88rem;color:var(--accent)}\n.cmd-card .cmd-line{\n display:block;background:var(--code-bg);padding:.3rem .5rem;border-radius:4px;\n font-family:monospace;font-size:.8rem;margin-bottom:.3rem;overflow-x:auto;\n}\n.cmd-card .desc{font-size:.8rem;color:var(--muted)}\n\n\/* \u6b65\u9aa4\u6709\u5e8f\u5217\u8868 *\/\n.step-list{\n list-style:none;counter-reset:step;margin:1.2rem 0;\n}\n.step-list li{\n counter-increment:step;position:relative;padding:.9rem 1rem .9rem 3rem;\n margin-bottom:.6rem;background:var(--card-bg);border-left:2px solid var(--rule);\n border-radius:0 var(--radius) var(--radius) 0;box-shadow:var(--shadow);\n}\n.step-list li::before{\n content:counter(step);position:absolute;left:-14px;top:.9rem;\n width:28px;height:28px;border-radius:50%;background:var(--accent);\n color:#fff;display:flex;align-items:center;justify-content:center;\n font-size:.78rem;font-weight:700;\n}\n.step-list .cmd-line{\n display:block;background:var(--code-bg);padding:.4rem .7rem;border-radius:5px;\n font-family:monospace;margin:.4rem 0;overflow-x:auto;font-size:.82rem;\n}\n\n\/* \u8868\u683c\u5bb9\u5668 *\/\n.table-box{overflow-x:auto;margin:1.2rem 0}\ntable{width:100%;border-collapse:collapse;font-size:.82rem}\nthead th{\n background:var(--accent);color:#fff;padding:.6rem .5rem;text-align:center;\n font-weight:600;\n}\nthead th:first-child{border-radius:6px 0 0 0}\nthead th:last-child{border-radius:0 6px 0 0}\ntbody td{padding:.6rem .5rem;border-bottom:1px solid var(--rule);vertical-align:middle}\ntbody tr:nth-child(even){background:var(--bg)}\ntbody td:first-child{text-align:left;font-weight:600}\n\n\/* \u5e95\u90e8 *\/\nfooter{\n max-width:var(--max-w);margin:4rem auto 0;padding:2rem 1rem 3rem;\n border-top:1px solid var(--rule);text-align:center;font-size:.82rem;color:var(--muted);\n}\n\n\/* \u79fb\u52a8\u7aef\u81ea\u9002\u5e94 \u7a84\u5c4f\u5168\u90e8\u81ea\u52a8\u5355\u5217\uff0c\u4e0d\u4f1a\u6392\u7248\u9519\u4e71 *\/\n@media (max-width:660px){\n h1{font-size:1.45rem}\n .compare-wrap{grid-template-columns:1fr}\n .cmd-grid{grid-template-columns:1fr}\n .step-list li{padding-left:2.5rem}\n .step-list li::before{width:24px;height:24px;left:-12px;font-size:.7rem}\n main{padding:74px 1rem 3rem}\n}\n<\/style>\n\n<header>\n <div class=\"header-wrap\">\n <div class=\"logo\"><span>\ud83e\udde9<\/span> DI\u4f9d\u8d56\u6ce8\u5165\u5bb9\u5668\u96f6\u57fa\u7840\u5b8c\u6574\u6559\u7a0b<\/div>\n <div class=\"header-ctrl\">\n <div class=\"lang-switch\">\n <button class=\"active\" onclick=\"switchLang('zh')\" id=\"btn-zh\">\u4e2d\u6587<\/button>\n <button onclick=\"switchLang('en')\" id=\"btn-en\">English<\/button>\n <\/div>\n <button class=\"theme-btn\" onclick=\"toggleDark()\" title=\"\u5207\u6362\u660e\u6697\u4e3b\u9898\">\u263c<\/button>\n <\/div>\n <\/div>\n<\/header>\n<main>\n<!-- \u4e2d\u6587\u5185\u5bb9\u533a\u5757 -->\n<div class=\"lang-block active\" id=\"zh-content\">\n <div class=\"hero\">\n <h1>DI\u4f9d\u8d56\u6ce8\u5165\u5bb9\u5668\u96f6\u57fa\u7840\u5b8c\u6574\u8bb2\u89e3<\/h1>\n <div class=\"desc-sub\">IoC\u3001\u4f9d\u8d56\u6ce8\u5165\u5927\u767d\u8bdd\u8bb2\u89e3\uff0cPython\u793a\u4f8b\u6f14\u793a\uff0c\u524d\u540e\u7aef\u901a\u7528\u8bbe\u8ba1\u601d\u60f3<\/div>\n <\/div>\n\n <div class=\"toc-box\">\n <h3>\u76ee\u5f55\u5bfc\u822a<\/h3>\n <ol>\n <li><a href=\"#part1\">\u4e00\u3001DI \/ IoC \/ \u5bb9\u5668 \u57fa\u7840\u6982\u5ff5<\/a><\/li>\n <li><a href=\"#part2\">\u4e8c\u3001\u4e0d\u4f7f\u7528DI\u5bb9\u5668\u7684\u4ee3\u7801\u75db\u70b9<\/a><\/li>\n <li><a href=\"#part3\">\u4e09\u3001DI\u5bb9\u5668\u4e09\u5927\u6838\u5fc3\u4f18\u52bf<\/a><\/li>\n <li><a href=\"#part4\">\u56db\u3001\u6ce8\u518c\u3001\u89e3\u6790\u3001\u751f\u547d\u5468\u671f\u6838\u5fc3\u672f\u8bed<\/a><\/li>\n <li><a href=\"#part5\">\u4e94\u3001\u624b\u5199\u8ff7\u4f60DI\u5bb9\u5668\uff0c\u770b\u61c2\u5e95\u5c42\u539f\u7406<\/a><\/li>\n <li><a href=\"#part6\">\u516d\u3001\u4e09\u79cd\u4f9d\u8d56\u6ce8\u5165\u65b9\u5f0f\u5bf9\u6bd4<\/a><\/li>\n <li><a href=\"#part7\">\u4e03\u3001\u670d\u52a1\u751f\u547d\u5468\u671f\uff1a\u5355\u4f8b\/\u77ac\u65f6\/\u4f5c\u7528\u57df<\/a><\/li>\n <li><a href=\"#part8\">\u516b\u3001\u65b0\u9879\u76ee\u6807\u51c6\u5b8c\u6574\u4f7f\u7528\u6d41\u7a0b<\/a><\/li>\n <li><a href=\"#part9\">\u4e5d\u3001\u5404\u8bed\u8a00\u6210\u719fDI\u5de5\u5177\u63a8\u8350<\/a><\/li>\n <li><a href=\"#part10\">\u5341\u3001\u65b0\u624b\u9ad8\u9891\u8e29\u5751\u4e0e\u89e3\u51b3\u65b9\u6848<\/a><\/li>\n <\/ol>\n <\/div>\n\n <h2 id=\"part1\">\u4e00\u3001DI \/ IoC \/ \u5bb9\u5668 \u57fa\u7840\u6982\u5ff5<\/h2>\n <div class=\"card\">\n <h4>\u96f6\u57fa\u7840\u901a\u4fd7\u89e3\u91ca<\/h4>\n <p><span class=\"tag-b\">\u4f9d\u8d56 Dependency<\/span>\uff1aA\u7c7b\u8fd0\u884c\u9700\u8981B\u7c7b\uff0cB\u5c31\u662fA\u7684\u4f9d\u8d56\u3002\u4f8b\u5982\u8ba2\u5355\u670d\u52a1\u9700\u8981\u6570\u636e\u5e93\u64cd\u4f5c\u7c7b\u3002<\/p>\n <p><span class=\"tag-g\">DI \u4f9d\u8d56\u6ce8\u5165<\/span>\uff1a\u4e0d\u5728\u7c7b\u5185\u90e8\u81ea\u5df1new\u4f9d\u8d56\u5bf9\u8c61\uff0c\u7531\u5916\u90e8\u628a\u4f9d\u8d56\u4f20\u5165\u7c7b\u4e2d\u4f7f\u7528\u3002<\/p>\n <p><span class=\"tag-p\">IoC \u63a7\u5236\u53cd\u8f6c<\/span>\uff1a\u4f20\u7edf\u4ee3\u7801\u81ea\u5df1\u521b\u5efa\u5bf9\u8c61\uff1bIoC\u628a\u5bf9\u8c61\u521b\u5efa\u3001\u7ba1\u7406\u7684\u63a7\u5236\u6743\u4ea4\u7ed9\u5bb9\u5668\u3002<\/p>\n <p><span class=\"tag-y\">DI\u5bb9\u5668<\/span>\uff1a\u7edf\u4e00\u5b58\u653e\u3001\u7ba1\u7406\u9879\u76ee\u6240\u6709\u670d\u52a1\u7684\u5de5\u5177\uff0c\u81ea\u52a8\u7ec4\u88c5\u4f9d\u8d56\uff0c\u5f00\u53d1\u8005\u65e0\u9700\u624b\u52a8\u5b9e\u4f8b\u5316\u5404\u7c7b\u5de5\u5177\u3002<\/p>\n <\/div>\n <div class=\"tip-box\">\n <strong>\u4e00\u53e5\u8bdd\u603b\u7ed3\uff1a<\/strong>DI\u5bb9\u5668\u7edf\u4e00\u7ba1\u7406\u9879\u76ee\u6240\u6709\u5de5\u5177\u7c7b\uff0c\u81ea\u52a8\u62fc\u63a5\u4f9d\u8d56\u5173\u7cfb\uff0c\u4f60\u53ea\u9700\u8981\u4e13\u6ce8\u5199\u4e1a\u52a1\u903b\u8f91\u3002\n <\/div>\n\n <h2 id=\"part2\">\u4e8c\u3001\u4e0d\u4f7f\u7528DI\u5bb9\u5668\u7684\u4ee3\u7801\u75db\u70b9<\/h2>\n <div class=\"compare-wrap\">\n <div class=\"compare-item bad\">\n <h4>\u4f20\u7edf\u786c\u7f16\u7801 new \u5199\u6cd5\u95ee\u9898<\/h4>\n <ul>\n <li>\u591a\u5c42\u4f9d\u8d56\u5d4c\u5957\uff0c\u5927\u91cf\u91cd\u590dnew\u4ee3\u7801<\/li>\n <li>\u4f9d\u8d56\u5199\u6b7b\uff0c\u5207\u6362\u6570\u636e\u5e93\/\u7f13\u5b58\u9700\u8981\u5927\u9762\u79ef\u6539\u4ee3\u7801<\/li>\n <li>\u5355\u5143\u6d4b\u8bd5\u65e0\u6cd5\u6a21\u62df\u4f9d\u8d56\uff0c\u5fc5\u987b\u8fde\u63a5\u771f\u5b9e\u4e2d\u95f4\u4ef6<\/li>\n <li>\u65e0\u6cd5\u7edf\u4e00\u7ba1\u63a7\u5355\u4f8b\uff0c\u91cd\u590d\u521b\u5efa\u5bf9\u8c61\u6d6a\u8d39\u5185\u5b58<\/li>\n <li>\u5e95\u5c42\u5de5\u5177\u4fee\u6539\u540e\uff0c\u4e0a\u5c42\u6240\u6709\u4e1a\u52a1\u4ee3\u7801\u8fde\u9501\u62a5\u9519<\/li>\n <\/ul>\n <\/div>\n <div class=\"compare-item good\">\n <h4>DI\u5bb9\u5668\u6807\u51c6\u5316\u89e3\u51b3\u65b9\u6848<\/h4>\n <ul>\n <li>\u6240\u6709\u670d\u52a1\u7edf\u4e00\u4e00\u5904\u6ce8\u518c\uff0c\u4f9d\u8d56\u96c6\u4e2d\u7ba1\u7406<\/li>\n <li>\u5207\u6362\u5e95\u5c42\u5b9e\u73b0\u4ec5\u4fee\u6539\u6ce8\u518c\u4ee3\u7801\uff0c\u4e1a\u52a1\u903b\u8f91\u96f6\u6539\u52a8<\/li>\n <li>\u6d4b\u8bd5\u65f6\u66ff\u6362Mock\u6a21\u62df\u670d\u52a1\uff0c\u5b8c\u5168\u9694\u79bb\u771f\u5b9e\u73af\u5883<\/li>\n <li>\u5185\u7f6e\u5355\u4f8b\/\u77ac\u65f6\u751f\u547d\u5468\u671f\uff0c\u81ea\u52a8\u590d\u7528\u5bf9\u8c61\u8282\u7701\u8d44\u6e90<\/li>\n <li>\u5e95\u5c42\u5de5\u5177\u8fed\u4ee3\u5347\u7ea7\uff0c\u4e0a\u5c42\u4e1a\u52a1\u4ee3\u7801\u65e0\u611f\u77e5<\/li>\n <\/ul>\n <\/div>\n <\/div>\n<pre class=\"code\">\n# \u53cd\u9762\u793a\u4f8b\uff1a\u5f3a\u8026\u5408\u786c\u7f16\u7801\nclass OrderService:\n def __init__(self):\n # \u5185\u90e8\u76f4\u63a5\u5b9e\u4f8b\u5316\uff0c\u65e0\u6cd5\u66ff\u6362\u6570\u636e\u5e93\u5b9e\u73b0\n self.db = MysqlDB()\n self.cache = RedisCache()\n self.notify = EmailNotify()\n<\/pre>\n\n <h2 id=\"part3\">\u4e09\u3001DI\u5bb9\u5668\u4e09\u5927\u6838\u5fc3\u4f18\u52bf<\/h2>\n <div class=\"cmd-grid\">\n <div class=\"cmd-card\">\n <h4>1. \u4ee3\u7801\u89e3\u8026<\/h4>\n <div class=\"desc\">\u4e1a\u52a1\u4ec5\u4f9d\u8d56\u62bd\u8c61\u63a5\u53e3\uff0c\u6570\u636e\u5e93\u3001\u7f13\u5b58\u5b9e\u73b0\u53ef\u65e0\u7f1d\u5207\u6362\uff0c\u65e0\u5f3a\u7ed1\u5b9a\u3002<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>2. \u5355\u5143\u6d4b\u8bd5\u6781\u7b80<\/h4>\n <div class=\"desc\">\u6d4b\u8bd5\u9636\u6bb5\u6ce8\u518cMock\u6a21\u62df\u670d\u52a1\uff0c\u4e0d\u7528\u542f\u52a8\u771f\u5b9e\u6570\u636e\u5e93\uff0c\u6d4b\u8bd5\u901f\u5ea6\u5927\u5e45\u63d0\u5347\u3002<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>3. \u6613\u6269\u5c55\u7ef4\u62a4<\/h4>\n <div class=\"desc\">\u65b0\u589e\u5de5\u5177\u4ec5\u6dfb\u52a0\u4e00\u884c\u6ce8\u518c\u4ee3\u7801\uff0c\u4e0d\u4fb5\u5165\u4e1a\u52a1\u903b\u8f91\uff0c\u540e\u671f\u7ef4\u62a4\u6210\u672c\u4f4e\u3002<\/div>\n <\/div>\n <\/div>\n\n <h2 id=\"part4\">\u56db\u3001\u6ce8\u518c\u3001\u89e3\u6790\u3001\u751f\u547d\u5468\u671f\u6838\u5fc3\u672f\u8bed<\/h2>\n <div class=\"card\">\n <h3>1. \u6ce8\u518c Register<\/h3>\n <p>\u544a\u77e5\u5bb9\u5668\uff1a\u62bd\u8c61\u63a5\u53e3\u5bf9\u5e94\u54ea\u4e2a\u5b9e\u73b0\u3001\u5bf9\u8c61\u662f\u5355\u4f8b\u8fd8\u662f\u6bcf\u6b21\u65b0\u5efa\u3002\u76f8\u5f53\u4e8e\u7ed9\u4ed3\u5e93\u767b\u8bb0\u5546\u54c1\u3002<\/p>\n<pre class=\"code\">\n# \u4f2a\u4ee3\u7801\u6ce8\u518c\u793a\u4f8b\ncontainer.register(DBInterface, MysqlDB, singleton=True)\ncontainer.register(CacheInterface, RedisCache)\n<\/pre>\n <h3>2. \u89e3\u6790 Resolve<\/h3>\n <p>\u4e1a\u52a1\u9700\u8981\u670d\u52a1\u65f6\u5411\u5bb9\u5668\u7d22\u53d6\u5b9e\u4f8b\uff1b\u5bb9\u5668\u81ea\u52a8\u9012\u5f52\u521b\u5efa\u6240\u6709\u4f9d\u8d56\u3001\u5b8c\u6210\u6ce8\u5165\uff0c\u76f4\u63a5\u8fd4\u56de\u5b8c\u6574\u53ef\u7528\u5bf9\u8c61\u3002<\/p>\n<pre class=\"code\">\n# \u89e3\u6790\u8ba2\u5355\u670d\u52a1\uff0c\u81ea\u52a8\u6ce8\u5165DB\u3001Cache\u4f9d\u8d56\norder_service = container.resolve(OrderService)\norder_service.create_order()\n<\/pre>\n <h3>3. \u751f\u547d\u5468\u671f Lifetime<\/h3>\n <p>\u63a7\u5236\u5bb9\u5668\u521b\u5efa\u5bf9\u8c61\u7684\u590d\u7528\u89c4\u5219\uff0c\u5206\u4e3a\u5355\u4f8b\u3001\u77ac\u65f6\u3001\u4f5c\u7528\u57df\u4e09\u7c7b\u3002<\/p>\n <\/div>\n\n <h2 id=\"part5\">\u4e94\u3001\u624b\u5199\u8ff7\u4f60DI\u5bb9\u5668\uff0c\u770b\u61c2\u5e95\u5c42\u539f\u7406<\/h2>\n <div class=\"tip-box\">\n <strong>\u5b66\u4e60\u7528\u9014\uff1a<\/strong>\u65e0\u7b2c\u4e09\u65b9\u5e93\u6781\u7b80\u5b9e\u73b0\uff0c\u4ec5\u6f14\u793a\u5bb9\u5668\u5e95\u5c42\u903b\u8f91\uff0c\u751f\u4ea7\u9879\u76ee\u4e0d\u8981\u624b\u5199\u3002\n <\/div>\n<pre class=\"code\">\n# Python\u6781\u7b80DI\u5bb9\u5668\u5b9e\u73b0\nclass MiniDIContainer:\n def __init__(self):\n self.registry = {} # \u5b58\u50a8\u62bd\u8c61\u4e0e\u5b9e\u73b0\u6620\u5c04\n self.singleton_cache = {} # \u7f13\u5b58\u5168\u5c40\u5355\u4f8b\n\n # \u7ed1\u5b9a\u62bd\u8c61\u4e0e\u5b9e\u73b0\uff0c\u8bbe\u7f6e\u662f\u5426\u5355\u4f8b\n def register(self, abstract_cls, impl_cls, singleton=False):\n self.registry[abstract_cls] = (impl_cls, singleton)\n\n # \u9012\u5f52\u89e3\u6790\u6240\u6709\u4f9d\u8d56\uff0c\u81ea\u52a8\u6ce8\u5165\n def resolve(self, target_cls):\n # \u547d\u4e2d\u5355\u4f8b\u7f13\u5b58\u76f4\u63a5\u8fd4\u56de\n if target_cls in self.singleton_cache:\n return self.singleton_cache[target_cls]\n impl_cls, is_singleton = self.registry.get(target_cls, (target_cls, False))\n\n # \u8bfb\u53d6\u6784\u9020\u51fd\u6570\u4f9d\u8d56\u6ce8\u89e3\n import inspect\n sig = inspect.signature(impl_cls.__init__)\n deps = []\n for param in sig.parameters.values():\n if param.annotation != param.empty:\n deps.append(self.resolve(param.annotation))\n instance = impl_cls(*deps)\n # \u5355\u4f8b\u5b58\u5165\u7f13\u5b58\u590d\u7528\n if is_singleton:\n self.singleton_cache[target_cls] = instance\n return instance\n\n# \u4f7f\u7528\u6f14\u793a\ncontainer = MiniDIContainer()\nclass DB: pass\nclass MysqlDB(DB): pass\ncontainer.register(DB, MysqlDB, singleton=True)\n\nclass OrderService:\n def __init__(self, db: DB):\n self.db = db\n def create(self):\n print(\"\u521b\u5efa\u8ba2\u5355\uff0c\u4f7f\u7528\u6570\u636e\u5e93\", self.db)\n\nsvc = container.resolve(OrderService)\nsvc.create()\n<\/pre>\n <div class=\"tip-box warn\">\n <strong>\u751f\u4ea7\u63d0\u793a\uff1a<\/strong>\u7b80\u6613\u5bb9\u5668\u7f3a\u5c11\u5faa\u73af\u4f9d\u8d56\u68c0\u6d4b\u3001\u8bf7\u6c42\u4f5c\u7528\u57df\u7b49\u80fd\u529b\uff0c\u9879\u76ee\u5f00\u53d1\u4f7f\u7528\u6210\u719f\u5f00\u6e90DI\u5e93\u3002\n <\/div>\n\n <h2 id=\"part6\">\u516d\u3001\u4e09\u79cd\u4f9d\u8d56\u6ce8\u5165\u65b9\u5f0f\u5bf9\u6bd4<\/h2>\n <div class=\"compare-wrap\">\n <div class=\"compare-item good\">\n <h4>\u6784\u9020\u6ce8\u5165\uff08\u63a8\u8350\u9996\u9009\uff09<\/h4>\n <p>\u4f9d\u8d56\u5168\u90e8\u5199\u5728\u6784\u9020\u51fd\u6570\u5165\u53c2\uff0c\u5b9e\u4f8b\u5316\u5f3a\u5236\u4f20\u5165\uff0c\u4f9d\u8d56\u6e05\u6670\u3001\u4e0d\u4f1a\u7f3a\u5931\uff0c\u5355\u5143\u6d4b\u8bd5\u6700\u53cb\u597d\u3002<\/p>\n<pre class=\"code\">\nclass OrderService:\n def __init__(self, db: DB, cache: Cache):\n self.db = db\n self.cache = cache\n<\/pre>\n <\/div>\n <div class=\"compare-item\">\n <h4>\u5c5e\u6027\u6ce8\u5165\uff08\u4ec5\u53ef\u9009\u4f9d\u8d56\uff09<\/h4>\n <p>\u5bf9\u8c61\u521b\u5efa\u5b8c\u6210\u540e\u5bb9\u5668\u8d4b\u503c\uff0c\u9002\u5408\u975e\u5fc5\u9700\u4f9d\u8d56\uff0c\u5bb9\u6613\u51fa\u73b0\u4f9d\u8d56\u672a\u6ce8\u5165\u7a7a\u503c\u62a5\u9519\u3002<\/p>\n<pre class=\"code\">\nclass OrderService:\n db: DB = None\n cache: Cache = None\n<\/pre>\n <\/div>\n <\/div>\n <div class=\"card\">\n <h4>\u65b9\u6cd5\u6ce8\u5165\uff08\u4e1a\u52a1\u6781\u5c11\u4f7f\u7528\uff09<\/h4>\n <p>\u901a\u8fc7\u4e13\u7528\u65b9\u6cd5\u4f20\u5165\u4e34\u65f6\u4f9d\u8d56\uff0c\u591a\u7528\u4e8e\u6846\u67b6\u94a9\u5b50\u3001\u56de\u8c03\u573a\u666f\uff0c\u5e38\u89c4\u4e1a\u52a1\u4ee3\u7801\u4e0d\u63a8\u8350\u3002<\/p>\n <\/div>\n\n <h2 id=\"part7\">\u4e03\u3001\u670d\u52a1\u751f\u547d\u5468\u671f\uff1a\u5355\u4f8b\/\u77ac\u65f6\/\u4f5c\u7528\u57df<\/h2>\n <div class=\"table-box\">\n <table>\n <thead>\n <tr>\n <th>\u751f\u547d\u5468\u671f\u7c7b\u578b<\/th>\n <th>\u5bf9\u8c61\u521b\u5efa\u89c4\u5219<\/th>\n <th>\u9002\u7528\u4e1a\u52a1\u573a\u666f<\/th>\n <\/tr>\n <\/thead>\n <tbody>\n <tr>\n <td>\u5355\u4f8b Singleton<\/td>\n <td>\u7a0b\u5e8f\u5168\u5c40\u4ec51\u4e2a\u5b9e\u4f8b\uff0c\u5168\u7a0b\u590d\u7528<\/td>\n <td>\u6570\u636e\u5e93\u8fde\u63a5\u6c60\u3001Redis\u5ba2\u6237\u7aef\u3001\u5168\u5c40\u914d\u7f6e<\/td>\n <\/tr>\n <tr>\n <td>\u77ac\u65f6 Transient<\/td>\n <td>\u6bcf\u6b21Resolve\u90fd\u751f\u6210\u5168\u65b0\u5bf9\u8c61<\/td>\n <td>\u8f7b\u91cf\u65e0\u72b6\u6001\u5de5\u5177\u3001\u4e34\u65f6\u8ba1\u7b97\u7c7b<\/td>\n <\/tr>\n <tr>\n <td>\u4f5c\u7528\u57df Scoped<\/td>\n <td>\u5355\u6b21\u8bf7\u6c42\/\u4f1a\u8bdd\u5171\u75281\u4e2a\u5b9e\u4f8b\uff0c\u8de8\u8bf7\u6c42\u9694\u79bb<\/td>\n <td>Web\u63a5\u53e3\u8bf7\u6c42\u4e0a\u4e0b\u6587\u3001\u4e8b\u52a1\u4f1a\u8bdd<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n\n <h2 id=\"part8\">\u516b\u3001\u65b0\u9879\u76ee\u6807\u51c6\u5b8c\u6574\u4f7f\u7528\u6d41\u7a0b<\/h2>\n <ol class=\"step-list\">\n <li>\u5b9a\u4e49\u6570\u636e\u5e93\u3001\u7f13\u5b58\u3001\u6d88\u606f\u901a\u77e5\u7b49\u5e95\u5c42\u62bd\u8c61\u63a5\u53e3\uff0c\u9694\u79bb\u5177\u4f53\u5b9e\u73b0\uff1b<\/li>\n <li>\u7a0b\u5e8f\u542f\u52a8\u65f6\u521d\u59cb\u5316\u5168\u5c40\u552f\u4e00DI\u5bb9\u5668\uff1b<\/li>\n <li>\u6279\u91cf\u6ce8\u518c\u6240\u6709\u5e95\u5c42\u5de5\u5177\uff0c\u533a\u5206\u5355\u4f8b\/\u77ac\u65f6\u751f\u547d\u5468\u671f\uff1b<\/li>\n <li>\u6ce8\u518c\u8ba2\u5355\u3001\u7528\u6237\u3001\u652f\u4ed8\u7b49\u5168\u90e8\u4e1a\u52a1\u670d\u52a1\uff1b<\/li>\n <li>\u9879\u76ee\u5165\u53e3\u6587\u4ef6\u4ece\u5bb9\u5668Resolve\u9876\u5c42\u4e1a\u52a1\u670d\u52a1\uff1b<\/li>\n <li>\u5168\u7a0b\u7981\u6b62\u624b\u52a8new\uff0c\u4e1a\u52a1\u4ee3\u7801\u4ec5\u4f9d\u8d56\u62bd\u8c61\u63a5\u53e3\uff1b<\/li>\n <li>\u5355\u5143\u6d4b\u8bd5\u65f6\u91cd\u65b0\u6ce8\u518cMock\u5b9e\u73b0\uff0c\u65e0\u9700\u4fee\u6539\u4e1a\u52a1\u4ee3\u7801\uff1b<\/li>\n <\/ol>\n\n <h2 id=\"part9\">\u4e5d\u3001\u5404\u8bed\u8a00\u6210\u719fDI\u5de5\u5177\u63a8\u8350<\/h2>\n <div class=\"cmd-grid\">\n <div class=\"cmd-card\">\n <h4>Python<\/h4>\n <div class=\"cmd-line\">dependency-inject\u3001lagom\u3001inject<\/div>\n <div class=\"desc\">\u9002\u914dFastAPI\/Flask\uff0c\u8f7b\u91cf\u65e0\u4fb5\u5165<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>Java<\/h4>\n <div class=\"cmd-line\">Spring IoC\u3001Guice\u3001Dagger<\/div>\n <div class=\"desc\">Spring\u5185\u7f6e\u5bb9\u5668\uff0c\u4f01\u4e1a\u5f00\u53d1\u884c\u4e1a\u6807\u51c6<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>TypeScript\/NodeJS<\/h4>\n <div class=\"cmd-line\">tsyringe\u3001TypeDI\u3001NestDI<\/div>\n <div class=\"desc\">Nest\u6846\u67b6\u539f\u751f\u4f9d\u8d56\u6ce8\u5165\u65b9\u6848<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>.NET C#<\/h4>\n <div class=\"cmd-line\">Microsoft.Extensions.DI<\/div>\n <div class=\"desc\">\u5b98\u65b9\u5185\u7f6e\uff0cASP.NET Web\u6807\u914d\u5bb9\u5668<\/div>\n <\/div>\n <\/div>\n\n <h2 id=\"part10\">\u5341\u3001\u65b0\u624b\u9ad8\u9891\u8e29\u5751\u4e0e\u89e3\u51b3\u65b9\u6848<\/h2>\n <div class=\"tip-box danger\">\n <strong>\u57511\uff1a\u5faa\u73af\u4f9d\u8d56\uff08A\u4f9d\u8d56B\uff0cB\u53c8\u4f9d\u8d56A\uff09<\/strong>\n <p>\u5bb9\u5668\u89e3\u6790\u65f6\u65e0\u9650\u9012\u5f52\u76f4\u63a5\u62a5\u9519\uff1b\u89e3\u51b3\uff1a\u62c6\u5206\u4e1a\u52a1\u6a21\u5757\uff0c\u62bd\u53d6\u516c\u5171\u4e2d\u95f4\u670d\u52a1\u6d88\u9664\u53cc\u5411\u4f9d\u8d56\u3002<\/p>\n <\/div>\n <div class=\"tip-box warn\">\n <strong>\u57512\uff1a\u5355\u4f8b\u6ce8\u5165\u77ac\u65f6\u5bf9\u8c61<\/strong>\n <p>\u5355\u4f8b\u4ec5\u521d\u59cb\u5316\u4e00\u6b21\uff0c\u5185\u90e8\u77ac\u65f6\u4f9d\u8d56\u6c38\u4e45\u56fa\u5b9a\u65e0\u6cd5\u5237\u65b0\uff1b\u89e3\u51b3\uff1a\u5355\u4f8b\u5185\u901a\u8fc7\u5bb9\u5668\u5de5\u5382\u52a8\u6001\u83b7\u53d6\u5b9e\u4f8b\u3002<\/p>\n <\/div>\n <div class=\"tip-box\">\n <strong>\u57513\uff1a\u4e1a\u52a1\u4ee3\u7801\u624b\u52a8new\u5b9e\u4f8b<\/strong>\n <p>\u7ed5\u5f00\u5bb9\u5668\u7ba1\u7406\uff0c\u5f7b\u5e95\u5931\u53bb\u89e3\u8026\u3001\u5355\u5143\u6d4b\u8bd5\u5168\u90e8\u4f18\u52bf\uff1b\u89c4\u8303\uff1a\u6240\u6709\u5b9e\u4f8b\u7edf\u4e00\u4ea4\u7ed9\u5bb9\u5668\u6ce8\u518c\u89e3\u6790\u3002<\/p>\n <\/div>\n<\/div>\n\n<!-- \u82f1\u6587\u5185\u5bb9\u533a\u5757 -->\n<div class=\"lang-block\" id=\"en-content\">\n <div class=\"hero\">\n <h1>DI Container Full Beginner Tutorial<\/h1>\n <div class=\"desc-sub\">IoC & Dependency Injection Guide, cross-language Python examples<\/div>\n <\/div>\n\n <div class=\"toc-box\">\n <h3>Table of Contents<\/h3>\n <ol>\n <li><a href=\"#e1\">1 Core Concept: DI \/ IoC \/ Container<\/a><\/li>\n <li><a href=\"#e2\">2 Pain Points Without DI Container<\/a><\/li>\n <li><a href=\"#e3\">3 Three Core Advantages<\/a><\/li>\n <li><a href=\"#e4\">4 Core Terms: Register \/ Resolve \/ Lifetime<\/a><\/li>\n <li><a href=\"#e5\">5 Minimal Handwritten DI Container Demo<\/a><\/li>\n <li><a href=\"#e6\">6 Three Injection Types Comparison<\/a><\/li>\n <li><a href=\"#e7\">7 Service Lifetime Rules<\/a><\/li>\n <li><a href=\"#e8\">8 Standard New Project Workflow<\/a><\/li>\n <li><a href=\"#e9\">9 Popular DI Libraries For All Languages<\/a><\/li>\n <li><a href=\"#e10\">10 Common Mistakes & Fixes<\/a><\/li>\n <\/ol>\n <\/div>\n\n <h2 id=\"e1\">1 Core Concept Explanation<\/h2>\n <div class=\"card\">\n <h4>Plain Language Definition<\/h4>\n <p><span class=\"tag-b\">Dependency<\/span>: Class A requires Class B to execute logic.<\/p>\n <p><span class=\"tag-g\">DI (Dependency Injection)<\/span>: Pass dependencies externally instead of instantiating inside class.<\/p>\n <p><span class=\"tag-p\">IoC (Inversion of Control)<\/span>: Move object creation control from business code to container.<\/p>\n <p><span class=\"tag-y\">DI Container<\/span>: Central service warehouse to register, instantiate and auto inject all dependencies.<\/p>\n <\/div>\n\n <h2 id=\"e2\">2 Pain Points Of Hardcoded New()<\/h2>\n <div class=\"compare-wrap\">\n <div class=\"compare-item bad\">\n <h4>Traditional Hardcode Drawbacks<\/h4>\n <ul>\n <li>Tight coupling between service and database implementation<\/li>\n <li>Hard to write isolated unit tests with real middleware<\/li>\n <li>Duplicate object instances waste memory<\/li>\n <li>Modifying base service breaks all upper-level business code<\/li>\n <\/ul>\n <\/div>\n <div class=\"compare-item good\">\n <h4>DI Container Solutions<\/h4>\n <ul>\n <li>Loose coupling via abstract interface<\/li>\n <li>Mock service registration for fast unit test<\/li>\n <li>Built-in singleton \/ transient lifetime control<\/li>\n <li>Centralized service registration, easy to maintain & extend<\/li>\n <\/ul>\n <\/div>\n <\/div>\n\n <h2 id=\"e3\">3 Three Core Advantages<\/h2>\n <div class=\"cmd-grid\">\n <div class=\"cmd-card\">\n <h4>1 Loose Coupling<\/h4>\n <div class=\"desc\">Depend on abstract interface instead of concrete implementation.<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>2 Test Friendly<\/h4>\n <div class=\"desc\">Replace real services with mock during testing without database connection.<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>3 Easy Extend<\/h4>\n <div class=\"desc\">Add new service only add one register line, no invasion to business code.<\/div>\n <\/div>\n <\/div>\n\n <h2 id=\"e4\">4 Core Terminology<\/h2>\n <div class=\"card\">\n <h3>Register<\/h3>\n <p>Bind abstract type to concrete class, define service lifetime rule.<\/p>\n <h3>Resolve<\/h3>\n <p>Request instance from container, auto resolve all nested dependencies recursively.<\/p>\n <h3>Lifetime<\/h3>\n <p>Rules to control object reuse: Singleton \/ Transient \/ Scoped.<\/p>\n <\/div>\n\n <h2 id=\"e5\">5 Minimal DI Container Demo Code<\/h2>\n<pre class=\"code\">\nclass MiniDIContainer:\n def __init__(self):\n self.registry = {}\n self.singleton_cache = {}\n def register(self, abstract, impl, singleton=False):\n self.registry[abstract] = (impl, singleton)\n def resolve(self, target):\n if target in self.singleton_cache:\n return self.singleton_cache[target]\n impl, is_singleton = self.registry.get(target, (target, False))\n import inspect\n sig = inspect.signature(impl.__init__)\n deps = []\n for param in sig.parameters.values():\n if param.annotation != param.empty:\n deps.append(self.resolve(param.annotation))\n instance = impl(*deps)\n if is_singleton:\n self.singleton_cache[target] = instance\n return instance\n<\/pre>\n\n <h2 id=\"e6\">6 Three Injection Modes Comparison<\/h2>\n <div class=\"compare-wrap\">\n <div class=\"compare-item good\">\n <h4>Constructor Injection (Recommended)<\/h4>\n <p>Dependencies passed via constructor, mandatory & explicit, best for unit test.<\/p>\n <\/div>\n <div class=\"compare-item\">\n <h4>Property Injection<\/h4>\n <p>Inject after instance created, only for optional dependencies.<\/p>\n <\/div>\n <\/div>\n <div class=\"card\">\n <h4>Method Injection (Rarely Used)<\/h4>\n <p>Inject temporary dependencies via dedicated function, only for framework callbacks.<\/p>\n <\/div>\n\n <h2 id=\"e7\">7 Service Lifetime Table<\/h2>\n <div class=\"table-box\">\n <table>\n <thead>\n <tr>\n <th>Lifetime<\/th>\n <th>Rule<\/th>\n <th>Applicable Scene<\/th>\n <\/tr>\n <\/thead>\n <tbody>\n <tr>\n <td>Singleton<\/td>\n <td>One global instance for whole app<\/td>\n <td>DB pool, Redis client, global config<\/td>\n <\/tr>\n <tr>\n <td>Transient<\/td>\n <td>New instance every resolve call<\/td>\n <td>Stateless lightweight utility<\/td>\n <\/tr>\n <tr>\n <td>Scoped<\/td>\n <td>One instance per single request\/session<\/td>\n <td>Web request context, transaction session<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n <\/div>\n\n <h2 id=\"e8\">8 Standard Production Workflow<\/h2>\n <ol class=\"step-list\">\n <li>Define abstract interfaces for external database\/cache services<\/li>\n <li>Initialize global DI container when app starts<\/li>\n <li>Register all base services with lifetime configuration<\/li>\n <li>Register all domain business services<\/li>\n <li>Resolve top-level service at app entry file<\/li>\n <li>Never manually new() objects in business logic<\/li>\n <li>Register mock implementation during unit testing<\/li>\n <\/ol>\n\n <h2 id=\"e9\">9 Popular DI Libraries By Language<\/h2>\n <div class=\"cmd-grid\">\n <div class=\"cmd-card\">\n <h4>Python<\/h4>\n <div class=\"cmd-line\">lagom, dependency-inject, inject<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>Java<\/h4>\n <div class=\"cmd-line\">Spring IoC, Guice, Dagger<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>TS\/JS<\/h4>\n <div class=\"cmd-line\">tsyringe, TypeDI, NestDI<\/div>\n <\/div>\n <div class=\"cmd-card\">\n <h4>.NET C#<\/h4>\n <div class=\"cmd-line\">Microsoft.Extensions.DependencyInjection<\/div>\n <\/div>\n <\/div>\n\n <h2 id=\"e10\">10 Common Pitfalls & Solutions<\/h2>\n <div class=\"tip-box danger\">\n <strong>Circular Dependency<\/strong>\n <p>Class A depends B, B depends A \u2192 split modules to eliminate bidirectional dependency.<\/p>\n <\/div>\n <div class=\"tip-box warn\">\n <strong>Singleton inject Transient service<\/strong>\n <p>Transient object frozen inside singleton, use factory pattern to fetch instance dynamically.<\/p>\n <\/div>\n <div class=\"tip-box\">\n <strong>Mix manual new() with container<\/strong>\n <p>Lose all decoupling and unit testing advantages, manage all services via container only.<\/p>\n <\/div>\n<\/div>\n<\/main>\n<footer>\n <p>DI Container Beginner Tutorial | Powered by unified component style<\/p>\n<\/footer>\n\n<script>\n\/\/ \u8bed\u8a00\u5207\u6362\nfunction switchLang(lang){\n document.querySelectorAll('.lang-block').forEach(el=>el.classList.remove('active'));\n document.getElementById(lang+'-content').classList.add('active');\n document.querySelectorAll('.lang-switch button').forEach(btn=>btn.classList.remove('active'));\n document.getElementById('btn-'+lang).classList.add('active');\n document.documentElement.lang = lang === 'zh' ? 'zh-CN' : 'en';\n}\n\/\/ \u660e\u6697\u4e3b\u9898\u5207\u6362\nfunction toggleDark(){\n const root = document.documentElement;\n if(root.hasAttribute('data-theme')){\n root.removeAttribute('data-theme');\n localStorage.removeItem('theme');\n }else{\n root.setAttribute('data-theme','dark');\n localStorage.setItem('theme');\n }\n}\n\/\/ \u9875\u9762\u52a0\u8f7d\u521d\u59cb\u5316\nwindow.addEventListener('DOMContentLoaded',()=>{\n \/\/ \u8bfb\u53d6\u672c\u5730\u5b58\u50a8\u4e3b\u9898\n if(localStorage.getItem('theme') === 'dark'){\n document.documentElement.setAttribute('data-theme','dark');\n }\n \/\/ \u951a\u70b9\u5e73\u6ed1\u6eda\u52a8\u5b9a\u4f4d\n const hash = window.location.hash;\n if(hash){\n const target = document.querySelector(hash);\n if(target) setTimeout(()=>target.scrollIntoView({behavior:'smooth'}),120);\n }\n})\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>DI\u4f9d\u8d56\u6ce8\u5165\u5bb9\u5668\u96f6\u57fa\u7840\u5b8c\u6574\u6559\u7a0b \ud83e\udde9 DI\u4f9d\u8d56\u6ce8\u5165\u5bb9\u5668\u96f6\u57fa\u7840\u5b8c\u6574\u6559\u7a0b \u4e2d\u6587 English \u263c DI\u4f9d\u8d56\u6ce8\u5165\u5bb9\u5668 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,9],"tags":[],"class_list":["post-336","post","type-post","status-publish","format-standard","hentry","category-cad","category-ai"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/numsimlab.com\/index.php?rest_route=\/wp\/v2\/posts\/336","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/numsimlab.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/numsimlab.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/numsimlab.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/numsimlab.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=336"}],"version-history":[{"count":1,"href":"https:\/\/numsimlab.com\/index.php?rest_route=\/wp\/v2\/posts\/336\/revisions"}],"predecessor-version":[{"id":337,"href":"https:\/\/numsimlab.com\/index.php?rest_route=\/wp\/v2\/posts\/336\/revisions\/337"}],"wp:attachment":[{"href":"https:\/\/numsimlab.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=336"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/numsimlab.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=336"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/numsimlab.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=336"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}