{"id":203344,"date":"2025-05-22T11:15:59","date_gmt":"2025-05-22T03:15:59","guid":{"rendered":"https:\/\/server.hk\/cnblog\/203344\/"},"modified":"2025-05-22T11:15:59","modified_gmt":"2025-05-22T03:15:59","slug":"kotlin-%e4%b8%ad%e7%9a%84%e5%86%85%e8%81%94%e7%b1%bb%ef%bc%9a%e4%b8%ba%e4%bb%80%e4%b9%88%e3%80%81%e5%9c%a8%e5%93%aa%e9%87%8c%e4%bb%a5%e5%8f%8a%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8%e5%ae%83%e4%bb%ac","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/203344\/","title":{"rendered":"Kotlin \u4e2d\u7684\u5185\u8054\u7c7b\uff1a\u4e3a\u4ec0\u4e48\u3001\u5728\u54ea\u91cc\u4ee5\u53ca\u5982\u4f55\u4f7f\u7528\u5b83\u4eec"},"content":{"rendered":"

<\/b> <\/p>\n

Kotlin \u4e2d\u7684\u5185\u8054\u7c7b\uff1a\u4e3a\u4ec0\u4e48\u3001\u5728\u54ea\u91cc\u4ee5\u53ca\u5982\u4f55\u4f7f\u7528\u5b83\u4eec<\/h1>\n

<\/i>\u6536\u85cf<\/span> <\/p>\n

\u5b66\u4e60\u6587\u7ae0<\/span>\u8981\u52aa\u529b\uff0c\u4f46\u662f\u4e0d\u8981\u6025\uff01\u4eca\u5929\u7684\u8fd9\u7bc7\u6587\u7ae0\u300aKotlin \u4e2d\u7684\u5185\u8054\u7c7b\uff1a\u4e3a\u4ec0\u4e48\u3001\u5728\u54ea\u91cc\u4ee5\u53ca\u5982\u4f55\u4f7f\u7528\u5b83\u4eec\u300b<\/span>\u5c06\u4f1a\u4ecb\u7ecd\u5230<\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u4f60\u60f3\u6df1\u5165\u5b66\u4e60\u6587\u7ae0<\/span>\uff0c\u53ef\u4ee5\u5173\u6ce8\u6211\uff01\u6211\u4f1a\u6301\u7eed\u66f4\u65b0\u76f8\u5173\u6587\u7ae0\u7684\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u90fd\u80fd\u6709\u6240\u5e2e\u52a9\uff01<\/p>\n

<\/p>\n

kotlin \u4e2d\u7684\u5185\u8054\u7c7b\u5141\u8bb8\u60a8\u4f7f\u7528\u81ea\u5b9a\u4e49\u7c7b\u578b\u5305\u88c5\u5355\u4e2a\u503c\uff0c\u4ee5\u63d0\u9ad8\u4ee3\u7801\u5b89\u5168\u6027\u548c\u53ef\u8bfb\u6027\u3002\u4e0e\u5e38\u89c4\u7c7b\u4e0d\u540c\uff0c\u5185\u8054\u7c7b\u4e0d\u4f1a\u589e\u52a0\u8fd0\u884c\u65f6\u5f00\u9500\uff0c\u56e0\u4e3a\u5b83\u4eec\u7531\u7f16\u8bd1\u5668\u201c\u5185\u8054\u201d\uff0c\u8fd9\u610f\u5473\u7740\u5728\u8fd0\u884c\u65f6\u4e0d\u4f1a\u521b\u5efa\u5b9e\u9645\u5bf9\u8c61\u3002\u672c\u6587\u63a2\u8ba8\u4e86\u4e3a\u4ec0\u4e48\u4ee5\u53ca\u5728\u4f55\u5904\u4f7f\u7528\u5185\u8054\u7c7b\uff0c\u5b83\u4eec\u4e0e\u7c7b\u578b\u522b\u540d\u6709\u4f55\u4e0d\u540c\uff0c\u5e76\u5305\u542b\u793a\u4f8b\u3002<\/p>\n

\u4e3a\u4ec0\u4e48\u4f7f\u7528\u5185\u8054\u7c7b\uff1f <\/h2>\n
    \n
  1. \n

    \u7c7b\u578b\u5b89\u5168<\/strong>\uff1a\u5185\u8054\u7c7b\u6709\u52a9\u4e8e\u9632\u6b62\u610f\u5916\u4f7f\u7528\u76f8\u4f3c\u7684\u6570\u636e\u7c7b\u578b\u3002\u4f8b\u5982\uff0cuserid \u548c productid \u53ef\u80fd\u90fd\u8868\u793a\u4e3a\u5b57\u7b26\u4e32\uff0c\u4f46\u5b83\u4eec\u4e0d\u662f\u53ef\u4ee5\u4e92\u6362\u7684\u6982\u5ff5\u3002\u5185\u8054\u7c7b\u786e\u4fdd\u5b83\u4eec\u5728\u7f16\u8bd1\u65f6\u4fdd\u6301\u4e0d\u540c\u7684\u7c7b\u578b\u3002<\/p>\n<\/li>\n

  2. \n

    \u8fd0\u884c\u65f6\u6027\u80fd<\/strong>\uff1a\u901a\u8fc7\u5185\u8054\u7c7b\uff0ckotlin \u901a\u8fc7\u5c3d\u53ef\u80fd\u5185\u8054\u5305\u88c5\u503c\u6765\u6d88\u9664\u521b\u5efa\u5305\u88c5\u5668\u5bf9\u8c61\u7684\u9700\u8981\u3002\u8fd9\u4f7f\u5f97\u5b83\u4eec\u7684\u6027\u80fd\u66f4\u52a0\u9ad8\u6548\uff0c\u901a\u5e38\u4f1a\u4f20\u9012 id\u3001\u4ee3\u7801\u6216\u6807\u8bc6\u7b26\u7b49\u5c0f\u503c\u3002<\/p>\n<\/li>\n

  3. \n

    \u53ef\u8bfb\u4ee3\u7801<\/strong>\uff1a\u5185\u8054\u7c7b\u4e3a\u5176\u4ed6\u901a\u7528\u503c\u63d0\u4f9b\u6709\u610f\u4e49\u7684\u540d\u79f0\uff0c\u4f7f\u4ee3\u7801\u66f4\u4e0d\u8a00\u81ea\u660e\u4e14\u66f4\u6613\u4e8e\u7406\u89e3\u3002<\/p>\n<\/li>\n<\/ol>\n

    \u5b9a\u4e49\u5185\u8054\u7c7b <\/h2>\n

    \u8981\u5728 kotlin \u4e2d\u5b9a\u4e49\u5185\u8054\u7c7b\uff0c\u8bf7\u4f7f\u7528 @jvminline \u6ce8\u89e3\u548c\u503c\u7c7b\uff0c\u5e76\u786e\u4fdd\u5b83\u53ea\u5305\u542b\u4e00\u4e2a val \u5c5e\u6027\uff1a<\/p>\n

    @jvminline\nvalue class userid(val id: string)\n@jvminline\nvalue class productid(val id: string)\n\nfun fetchuser(userid: userid) {\n    println(\"fetching user with id: ${userid.id}\")\n}\n\nfun main() {\n    fetchuser(userid(\"1\")) \/\/ ok\n    fetchuser(productid(\"1\")) \/\/ not ok. even though inlined type is string\n}\n<\/pre>\n
    \u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0cuserid \u548c productid \u662f\u5305\u88c5 string \u7684\u5185\u8054\u7c7b\u3002\u5373\u4f7f\u5b83\u4eec\u5177\u6709\u76f8\u540c\u7684\u57fa\u7840\u7c7b\u578b\uff08string\uff09\uff0ckotlin \u4e5f\u4f1a\u5c06\u5b83\u4eec\u89c6\u4e3a\u4e0d\u540c\u7684\u7c7b\u578b\uff0c\u4ece\u800c\u9632\u6b62\u610f\u5916\u6df7\u6dc6\u3002<\/p>\n
     \u4f55\u65f6\u4f55\u5730\u4f7f\u7528\u5185\u8054\u7c7b <\/h2>\n
    \u5185\u8054\u7c7b\u5728\u60a8\u9700\u8981\u65f6\u7279\u522b\u6709\u7528\uff1a<\/p>\n
      \n
    1.  \u6362\u884c\u6807\u8bc6\u7b26\u6216\u4ee3\u7801<\/strong>\uff1a\u5f53\u60a8\u62e5\u6709\u552f\u4e00\u7684 id \u6216\u4ee3\u7801\uff08\u4f8b\u5982 userid\u3001productid\uff09\u5e76\u5e0c\u671b\u907f\u514d\u610f\u5916\u4ea4\u6362\u5b83\u4eec\u7684\u98ce\u9669\u65f6\u3002<\/li>\n
    2.  \u51cf\u5c11\u9ad8\u9891\u8c03\u7528\u7684\u5f00\u9500<\/strong>\uff1a\u5bf9\u4e8e\u6027\u80fd\u5f88\u91cd\u8981\u7684\u51fd\u6570\u6216 api\uff0c\u5185\u8054\u7c7b\u53ef\u4ee5\u907f\u514d\u521b\u5efa\u989d\u5916\u5bf9\u8c61\u7684\u6210\u672c\u3002<\/li>\n
    3.  \u5c01\u88c5\u7279\u5b9a\u4e8e\u57df\u7684\u7c7b\u578b<\/strong>\uff1a\u5b83\u4eec\u975e\u5e38\u9002\u5408\u8868\u793a\u7279\u5b9a\u4e8e\u57df\u7684\u7c7b\u578b\uff0c\u4f8b\u5982\u8d27\u5e01\u3001\u91cd\u91cf\u6216\u8ddd\u79bb\uff0c\u800c\u4e0d\u9700\u8981\u6210\u719f\u7684\u7c7b\u3002<\/li>\n<\/ol>\n
       \u4e0e\u7c7b\u578b\u522b\u540d\u7684\u6bd4\u8f83 <\/h2>\n
      kotlin \u4e2d\u7684\u7c7b\u578b\u522b\u540d\u662f\u53e6\u4e00\u79cd\u65e0\u9700\u521b\u5efa\u65b0\u7c7b\u578b\u5373\u53ef\u4e3a\u7c7b\u578b\u6dfb\u52a0\u542b\u4e49\u7684\u65b9\u6cd5\u3002\u7136\u800c\uff0c\u4e0e\u5185\u8054\u7c7b\u4e0d\u540c\uff0ctypealias \u4ec5\u5728\u7f16\u8bd1\u65f6\u521b\u5efa\u522b\u540d\uff0c\u800c\u6ca1\u6709\u5b9e\u9645\u7684\u7c7b\u578b\u5b89\u5168\u6027\uff1a<\/p>\n
      typealias UserId = String\ntypealias ProductId = String\n\nfun printProductId(id: ProductId) {\n    println(\"Product ID: $id\")\n}\n\n\/\/ The following would compile, even though it's an incorrect usage.\nval userId: UserId = \"user_id\"\nprintProductId(userId) \/\/ Will print Product ID: user_id\n<\/pre>\n
      \u4f7f\u7528 typealias\uff0cuserid \u548c productid \u53ea\u662f string \u7684\u522b\u540d\uff0c\u56e0\u6b64 kotlin \u5c06\u5b83\u4eec\u89c6\u4e3a\u53ef\u4e92\u6362\u7684\uff0c\u8fd9\u5b58\u5728\u610f\u5916\u8bef\u7528\u7684\u98ce\u9669\u3002\u5185\u8054\u7c7b\u901a\u8fc7\u5728\u7f16\u8bd1\u65f6\u4e3a userid \u548c productid \u521b\u5efa\u4e0d\u540c\u7684\u7c7b\u578b\u6765\u907f\u514d\u6b64\u95ee\u9898\u3002<\/p>\n
       \u7ed3\u8bba <\/h2>\n
      kotlin \u4e2d\u7684\u5185\u8054\u7c7b\u63d0\u4f9b\u4e86\u4e00\u79cd\u5f3a\u5927\u7684\u65b9\u6cd5\u6765\u6dfb\u52a0\u7c7b\u578b\u5b89\u5168\u6027\u3001\u63d0\u9ad8\u4ee3\u7801\u53ef\u8bfb\u6027\u5e76\u4f18\u5316\u503c\u7684\u8f7b\u91cf\u7ea7\u5305\u88c5\u5668\u7684\u6027\u80fd\u3002\u5b83\u4eec\u5bf9\u4e8e\u6807\u8bc6\u7b26\u6216\u5c0f\u503c\u7279\u522b\u6709\u7528\uff0c\u5426\u5219\u4f1a\u521b\u5efa\u4e0d\u5fc5\u8981\u7684\u5bf9\u8c61\u5206\u914d\u3002\u901a\u8fc7\u4f7f\u7528\u5185\u8054\u7c7b\uff0c\u60a8\u53ef\u4ee5\u4e24\u5168\u5176\u7f8e\uff1a\u7f16\u8bd1\u65f6\u5b89\u5168\u800c\u65e0\u9700\u8fd0\u884c\u65f6\u5f00\u9500\u3002<\/p>\n
      \u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300aKotlin \u4e2d\u7684\u5185\u8054\u7c7b\uff1a\u4e3a\u4ec0\u4e48\u3001\u5728\u54ea\u91cc\u4ee5\u53ca\u5982\u4f55\u4f7f\u7528\u5b83\u4eec\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03\u6587\u7ae0\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01<\/p>\n
            \u7248\u672c\u58f0\u660e \u672c\u6587\u8f6c\u8f7d\u4e8e\uff1adev.to \u5982\u6709\u4fb5\u72af\uff0c\u8bf7\u8054\u7cfb\u5220\u9664<\/p>\n","protected":false},"excerpt":{"rendered":"
      Kotlin \u4e2d\u7684\u5185\u8054\u7c7b\uff1a\u4e3a\u4ec0\u4e48...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-203344","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203344","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=203344"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203344\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=203344"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=203344"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=203344"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}