{"id":58455,"date":"2024-10-12T20:46:36","date_gmt":"2024-10-12T12:46:36","guid":{"rendered":"https:\/\/server.hk\/cnblog\/58455\/"},"modified":"2024-10-12T20:46:36","modified_gmt":"2024-10-12T12:46:36","slug":"android%e6%95%b8%e6%93%9a%e5%ba%ab%e6%8e%92%e5%ba%8f%ef%bc%9a%e5%a6%82%e4%bd%95%e5%84%aa%e5%8c%96%e6%95%b8%e6%93%9a%e6%8e%92%e5%ba%8f%e6%93%8d%e4%bd%9c%ef%bc%9f-android-%e6%95%b8%e6%93%9a%e5%ba%ab","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/58455\/","title":{"rendered":"Android\u6578\u64da\u5eab\u6392\u5e8f\uff1a\u5982\u4f55\u512a\u5316\u6578\u64da\u6392\u5e8f\u64cd\u4f5c\uff1f (android \u6578\u64da\u5eab\u6392\u5e8f)"},"content":{"rendered":"

Android\u6578\u64da\u5eab\u6392\u5e8f\uff1a\u5982\u4f55\u512a\u5316\u6578\u64da\u6392\u5e8f\u64cd\u4f5c\uff1f<\/h1>\n

\u5728Android\u958b\u767c\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u4f7f\u7528\u662f\u4e0d\u53ef\u6216\u7f3a\u7684\u4e00\u90e8\u5206\u3002\u7121\u8ad6\u662f\u4f7f\u7528SQLite\u9084\u662f\u5176\u4ed6\u6578\u64da\u5eab\u7cfb\u7d71\uff0c\u6578\u64da\u7684\u6392\u5e8f\u64cd\u4f5c\u90fd\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u5728Android\u4e2d\u512a\u5316\u6578\u64da\u6392\u5e8f\u64cd\u4f5c\uff0c\u4ee5\u63d0\u9ad8\u61c9\u7528\u7684\u6027\u80fd\u548c\u7528\u6236\u9ad4\u9a57\u3002<\/p>\n

1. \u7406\u89e3\u6578\u64da\u6392\u5e8f\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n

\u6578\u64da\u6392\u5e8f\u662f\u6307\u5c07\u6578\u64da\u6309\u7167\u7279\u5b9a\u7684\u9806\u5e8f\u6392\u5217\uff0c\u901a\u5e38\u662f\u5347\u5e8f\u6216\u964d\u5e8f\u3002\u5728Android\u4e2d\uff0c\u6578\u64da\u6392\u5e8f\u53ef\u4ee5\u901a\u904eSQL\u67e5\u8a62\u8a9e\u53e5\u4f86\u5be6\u73fe\uff0c\u4f8b\u5982\u4f7f\u7528ORDER BY\u5b50\u53e5\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684SQL\u67e5\u8a62\u793a\u4f8b\uff1a<\/p>\n

SELECT * FROM users ORDER BY age ASC;<\/code><\/pre>\n
\u9019\u689d\u67e5\u8a62\u5c07\u5f9eusers\u8868\u4e2d\u9078\u64c7\u6240\u6709\u8a18\u9304\uff0c\u4e26\u6839\u64da\u5e74\u9f61\u9032\u884c\u5347\u5e8f\u6392\u5e8f\u3002<\/p>\n
2. \u4f7f\u7528\u7d22\u5f15\u4f86\u512a\u5316\u6392\u5e8f\u6027\u80fd<\/h2>\n
\u5728\u6578\u64da\u5eab\u4e2d\uff0c\u7d22\u5f15\u662f\u4e00\u7a2e\u6578\u64da\u7d50\u69cb\uff0c\u53ef\u4ee5\u52a0\u901f\u67e5\u8a62\u64cd\u4f5c\u3002\u5c0d\u65bc\u9700\u8981\u6392\u5e8f\u7684\u5217\uff0c\u5275\u5efa\u7d22\u5f15\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u6027\u80fd\u3002\u4ee5\u4e0b\u662f\u5275\u5efa\u7d22\u5f15\u7684SQL\u8a9e\u53e5\u793a\u4f8b\uff1a<\/p>\n
CREATE INDEX idx_age ON users(age);<\/code><\/pre>\n
\u901a\u904e\u5728age\u5217\u4e0a\u5275\u5efa\u7d22\u5f15\uff0c\u6578\u64da\u5eab\u5728\u57f7\u884c\u6392\u5e8f\u64cd\u4f5c\u6642\u53ef\u4ee5\u66f4\u5feb\u5730\u627e\u5230\u6240\u9700\u7684\u6578\u64da\u3002<\/p>\n
3. \u6e1b\u5c11\u6578\u64da\u96c6\u7684\u5927\u5c0f<\/h2>\n
\u5728\u9032\u884c\u6392\u5e8f\u64cd\u4f5c\u4e4b\u524d\uff0c\u8003\u616e\u662f\u5426\u53ef\u4ee5\u901a\u904e\u904e\u6ffe\u689d\u4ef6\u4f86\u6e1b\u5c11\u6578\u64da\u96c6\u7684\u5927\u5c0f\u3002\u4f7f\u7528WHERE\u5b50\u53e5\u53ef\u4ee5\u6709\u6548\u5730\u9650\u5236\u67e5\u8a62\u7d50\u679c\u3002\u4f8b\u5982\uff1a<\/p>\n
SELECT * FROM users WHERE active = 1 ORDER BY age ASC;<\/code><\/pre>\n
\u9019\u6a23\u7684\u67e5\u8a62\u53ea\u6703\u8fd4\u56de\u6d3b\u8e8d\u7528\u6236\uff0c\u5f9e\u800c\u6e1b\u5c11\u4e86\u9700\u8981\u6392\u5e8f\u7684\u6578\u64da\u91cf\u3002<\/p>\n
4. \u4f7f\u7528\u5408\u9069\u7684\u6578\u64da\u7d50\u69cb<\/h2>\n
\u5728Android\u4e2d\uff0c\u4f7f\u7528\u5408\u9069\u7684\u6578\u64da\u7d50\u69cb\u53ef\u4ee5\u63d0\u9ad8\u6392\u5e8f\u64cd\u4f5c\u7684\u6548\u7387\u3002\u4f8b\u5982\uff0c\u4f7f\u7528ArrayList\u4f86\u5b58\u5132\u6578\u64da\uff0c\u7136\u5f8c\u4f7f\u7528Collections.sort()\u65b9\u6cd5\u9032\u884c\u6392\u5e8f\uff1a<\/p>\n
Collections.sort(userList, new Comparator() {\n    @Override\n    public int compare(User u1, User u2) {\n        return Integer.compare(u1.getAge(), u2.getAge());\n    }\n});<\/code><\/pre>\n
\u9019\u7a2e\u65b9\u6cd5\u9069\u5408\u65bc\u5c0f\u578b\u6578\u64da\u96c6\uff0c\u4f46\u5c0d\u65bc\u5927\u578b\u6578\u64da\u96c6\uff0c\u5efa\u8b70\u4f7f\u7528\u6578\u64da\u5eab\u7684\u6392\u5e8f\u529f\u80fd\u3002<\/p>\n
5. \u8003\u616e\u7570\u6b65\u8655\u7406<\/h2>\n
\u5728Android\u61c9\u7528\u4e2d\uff0c\u9032\u884c\u6578\u64da\u6392\u5e8f\u64cd\u4f5c\u6642\uff0c\u61c9\u8003\u616e\u4f7f\u7528\u7570\u6b65\u8655\u7406\uff0c\u4ee5\u907f\u514d\u963b\u585e\u4e3b\u7dda\u7a0b\u3002\u53ef\u4ee5\u4f7f\u7528AsyncTask\u6216\u5176\u4ed6\u7570\u6b65\u6846\u67b6\u4f86\u5be6\u73fe\uff1a<\/p>\n
new AsyncTask<Void, Void, List>() {\n    @Override\n    protected List doInBackground(Void... voids) {\n        return database.userDao().getAllUsersSortedByAge();\n    }\n\n    @Override\n    protected void onPostExecute(List users) {\n        \/\/ \u66f4\u65b0UI\n    }\n}.execute();<\/code><\/pre>\n
6. \u6e2c\u8a66\u548c\u8abf\u512a<\/h2>\n
\u6700\u5f8c\uff0c\u5c0d\u65bc\u4efb\u4f55\u6392\u5e8f\u64cd\u4f5c\uff0c\u6e2c\u8a66\u548c\u8abf\u512a\u90fd\u662f\u5fc5\u4e0d\u53ef\u5c11\u7684\u3002\u4f7f\u7528Android Profiler\u7b49\u5de5\u5177\u4f86\u76e3\u63a7\u61c9\u7528\u7684\u6027\u80fd\uff0c\u627e\u51fa\u74f6\u9838\u4e26\u9032\u884c\u76f8\u61c9\u7684\u512a\u5316\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u5728Android\u958b\u767c\u4e2d\uff0c\u512a\u5316\u6578\u64da\u6392\u5e8f\u64cd\u4f5c\u662f\u63d0\u9ad8\u61c9\u7528\u6027\u80fd\u7684\u95dc\u9375\u3002\u901a\u904e\u4f7f\u7528\u7d22\u5f15\u3001\u6e1b\u5c11\u6578\u64da\u96c6\u5927\u5c0f\u3001\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u7d50\u69cb\u3001\u8003\u616e\u7570\u6b65\u8655\u7406\u4ee5\u53ca\u9032\u884c\u6e2c\u8a66\u548c\u8abf\u512a\uff0c\u53ef\u4ee5\u986f\u8457\u63d0\u5347\u6392\u5e8f\u6548\u7387\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6027\u80fd\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u53ef\u9760\u7684 \u9999\u6e2fVPS<\/a> \u670d\u52d9\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22Android\u6578\u64da\u5eab\u6392\u5e8f\u7684\u6700\u4f73\u5be6\u8e10\uff0c\u5b78\u7fd2\u5982\u4f55\u512a\u5316\u6578\u64da\u6392\u5e8f\u64cd\u4f5c\u4ee5\u63d0\u5347\u61c9\u7528\u6027\u80fd\u548c\u7528\u6236\u9ad4\u9a57\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-58455","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/58455","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=58455"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/58455\/revisions"}],"predecessor-version":[{"id":58456,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/58455\/revisions\/58456"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=58455"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=58455"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=58455"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}