{"id":1555,"date":"2017-03-21T06:40:05","date_gmt":"2017-03-20T22:40:05","guid":{"rendered":"http:\/\/www.qdabc.cn\/?p=1555"},"modified":"2017-03-20T23:32:46","modified_gmt":"2017-03-20T15:32:46","slug":"%e9%87%8d%e6%9e%84%e4%b8%8e%e9%87%8d%e7%bb%98","status":"publish","type":"post","link":"http:\/\/www.qdabc.cn\/?p=1555","title":{"rendered":"\u91cd\u6784\u4e0e\u91cd\u7ed8"},"content":{"rendered":"

\u6d4f\u89c8\u5668\u7684\u6e32\u67d3\u8fc7\u7a0b<\/p>\n

1\uff0c\u6d4f\u89c8\u5668\u89e3\u6790html\u6e90\u7801\uff0c\u7136\u540e\u521b\u5efa\u4e00\u4e2a DOM\u6811\u3002
\n\u5728DOM\u6811\u4e2d\uff0c\u6bcf\u4e00\u4e2aHTML\u6807\u7b7e\u90fd\u6709\u4e00\u4e2a\u5bf9\u5e94\u7684\u8282\u70b9\uff0c\u5e76\u4e14\u6bcf\u4e00\u4e2a\u6587\u672c\u4e5f\u90fd\u4f1a\u6709\u4e00\u4e2a\u5bf9\u5e94\u7684\u6587\u672c\u8282\u70b9\u3002
\nDOM\u6811\u7684\u6839\u8282\u70b9\u5c31\u662f documentElement\uff0c\u5bf9\u5e94\u7684\u662fhtml\u6807\u7b7e\u3002<\/p>\n

2\uff0c\u6d4f\u89c8\u5668\u89e3\u6790CSS\u4ee3\u7801\uff0c\u8ba1\u7b97\u51fa\u6700\u7ec8\u7684\u6837\u5f0f\u6570\u636e\u3002
\n\u5bf9CSS\u4ee3\u7801\u4e2d\u975e\u6cd5\u7684\u8bed\u6cd5\u5979\u4f1a\u76f4\u63a5\u5ffd\u7565\u6389\u3002
\n\u89e3\u6790CSS\u7684\u65f6\u5019\u4f1a\u6309\u7167\u5982\u4e0b\u987a\u5e8f\u6765\u5b9a\u4e49\u4f18\u5148\u7ea7\uff1a\u6d4f\u89c8\u5668\u9ed8\u8ba4\u8bbe\u7f6e\uff0c\u7528\u6237\u8bbe\u7f6e\uff0c\u5916\u94fe\u6837\u5f0f\uff0c\u5185\u8054\u6837\u5f0f\uff0chtml\u4e2d\u7684style\u3002<\/p>\n

3\uff0c\u6784\u5efa\u51faDOM\u6811\uff0c\u5e76\u4e14\u8ba1\u7b97\u51fa\u6837\u5f0f\u6570\u636e\u540e\uff0c\u4e0b\u4e00\u6b65\u5c31\u662f\u6784\u5efa\u4e00\u4e2a \u6e32\u67d3\u6811\uff08rendering tree\uff09\u3002
\n\u6e32\u67d3\u6811\u548cDOM\u6811\u6709\u70b9\u50cf\uff0c\u4f46\u662f\u662f\u6709\u533a\u522b\u7684\u3002DOM\u6811\u5b8c\u5168\u548chtml\u6807\u7b7e\u4e00\u4e00\u5bf9\u5e94\uff0c\u4f46\u662f\u6e32\u67d3\u6811\u4f1a\u5ffd\u7565\u6389\u4e0d\u9700\u8981\u6e32\u67d3\u7684\u5143\u7d20\uff0c\u6bd4\u5982head\u3001display:none\u7684\u5143\u7d20\u7b49\u3002
\n\u800c\u4e14\u4e00\u5927\u6bb5\u6587\u672c\u4e2d\u7684\u6bcf\u4e00\u4e2a\u884c\u5728\u6e32\u67d3\u6811\u4e2d\u90fd\u662f\u72ec\u7acb\u7684\u4e00\u4e2a\u8282\u70b9\u3002
\n\u6e32\u67d3\u6811\u4e2d\u7684\u6bcf\u4e00\u4e2a\u8282\u70b9\u90fd\u5b58\u50a8\u6709\u5bf9\u5e94\u7684css\u5c5e\u6027\u3002<\/p>\n

4\uff0c\u4e00\u65e6\u6e32\u67d3\u6811\u521b\u5efa\u597d\u4e86\uff0c\u6d4f\u89c8\u5668\u5c31\u53ef\u4ee5\u6839\u636e\u6e32\u67d3\u6811\u76f4\u63a5\u628a\u9875\u9762\u7ed8\u5236\u5230\u5c4f\u5e55\u4e0a\u3002<\/p>\n

\u4e00\u4e2a\u6e32\u67d3\u8fc7\u7a0b\u7684\u4f8b\u5b50<\/p>\n

\u4f8b\u5982\u6709\u4e0b\u9762\u8fd9\u6837\u4e00\u6bb5HTML\u4ee3\u7801\uff1a<\/p>\n

<html>\r\n<head>\r\n  <title>Beautiful page<\/title>\r\n<\/head>\r\n<body>\r\n    \r\n  <p>\r\n    Once upon a time there was \r\n    a looong paragraph...\r\n  <\/p>\r\n  \r\n  <div style=\"display: none\">\r\n    Secret message\r\n  <\/div>\r\n  \r\n  <div><img src=\"...\" \/><\/div>\r\n  ...\r\n\r\n<\/body>\r\n<\/html><\/pre>\n
\u90a3\u4e48DOM\u6811\u662f\u5b8c\u5168\u548cHTML\u6807\u7b7e\u4e00\u4e00\u5bf9\u5e94\u7684\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n
documentElement (html)\r\nhead\r\ntitle\r\nbody\r\np\r\n[text node]\r\ndiv\r\n[text node]\r\ndiv\r\nimg\r\n...<\/pre>\n
\u800c\u6e32\u67d3\u6811\u5c31\u4e0d\u540c\u4e86\uff0c\u5979\u53ea\u6709\u54ea\u4e9b\u9700\u8981\u7ed8\u5236\u51fa\u6765\u7684\u5143\u7d20\uff0c\u6240\u4ee5head \u4ee5\u53ca\u88ab\u9690\u85cf\u7684div\u90fd\u4e0d\u4f1a\u51fa\u73b0\u5728\u6e32\u67d3\u6811\u4e2d\u3002<\/p>\n
root (RenderView)\r\nbody\r\np\r\nline 1\r\nline 2\r\nline 3\r\n...\r\n\r\ndiv\r\nimg\r\n\r\n...<\/pre>\n
\u91cd\u7ed8\u548c\u91cd\u6392\uff08repaints and reflows\uff09
\n\u6bcf\u4e2a\u9875\u9762\u81f3\u5c11\u5728\u521d\u59cb\u5316\u7684\u65f6\u5019\u4f1a\u6709\u4e00\u6b21\u91cd\u6392\u64cd\u4f5c\u3002\u4efb\u4f55\u5bf9\u6e32\u67d3\u6811\u7684\u4fee\u6539\u90fd\u6709\u53ef\u80fd\u4f1a\u5bfc\u81f4\u4e0b\u9762\u4e24\u79cd\u64cd\u4f5c\uff1a
\n1\uff0c\u91cd\u6392
\n\u5c31\u662f\u6e32\u67d3\u6811\u7684\u4e00\u90e8\u5206\u5fc5\u987b\u8981\u66f4\u65b0 \u5e76\u4e14\u8282\u70b9\u7684\u5c3a\u5bf8\u53d1\u751f\u4e86\u53d8\u5316\u3002\u8fd9\u5c31\u4f1a\u89e6\u53d1\u91cd\u6392\u64cd\u4f5c\u3002<\/p>\n
2\uff0c\u91cd\u7ed8
\n\u90e8\u5206\u8282\u70b9\u9700\u8981\u66f4\u65b0\uff0c\u4f46\u662f\u6ca1\u6709\u6539\u53d8\u4ed6\u7684\u96c6\u5408\u5f62\u72b6\uff0c\u6bd4\u5982\u6539\u53d8\u4e86\u80cc\u666f\u989c\u8272\uff0c\u8fd9\u5c31\u4f1a\u89e6\u53d1\u91cd\u7ed8\u3002<\/p>\n
\u4ec0\u4e48\u60c5\u51b5\u4e0b\u4f1a\u89e6\u53d1\u91cd\u7ed8\u6216\u91cd\u6392<\/p>\n
\u4e0b\u9762\u4efb\u4f55\u64cd\u4f5c\u90fd\u4f1a\u89e6\u53d1\u91cd\u7ed8\u6216\u8005\u91cd\u6392\uff1a<\/p>\n
\u589e\u52a0\u6216\u5220\u9664DOM\u8282\u70b9
\n\u8bbe\u7f6e display: none;\uff08\u91cd\u6392\u5e76\u91cd\u7ed8\uff09 \u6216\u8005 visibility: hidden\uff08\u53ea\u6709\u91cd\u6392\uff09
\n\u79fb\u52a8\u9875\u9762\u4e2d\u7684\u5143\u7d20
\n\u589e\u52a0\u6216\u8005\u4fee\u6539\u6837\u5f0f
\n\u7528\u6237 \u6539\u53d8\u7a97\u53e3\u5927\u5c0f\uff0c\u6eda\u52a8\u9875\u9762\u7b49
\n\u770b\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n
var bstyle = document.body.style; \/\/ cache\r\n\r\nbstyle.padding = \"20px\"; \/\/ reflow, repaint\r\nbstyle.border = \"10px solid red\"; \/\/ another reflow and a repaint\r\n\r\nbstyle.color = \"blue\"; \/\/ repaint only, no dimensions changed\r\nbstyle.backgroundColor = \"#fad\"; \/\/ repaint\r\n\r\nbstyle.fontSize = \"2em\"; \/\/ reflow, repaint\r\n\r\n\/\/ new DOM element - reflow, repaint\r\ndocument.body.appendChild(document.createTextNode('dude!'));<\/pre>\n
 <\/p>\n
\u6709\u4e9b\u91cd\u7ed8\u64cd\u4f5c\u4f1a\u6bd4\u5176\u4ed6\u64cd\u4f5c\u6602\u8d35\u5f88\u591a\u3002\u6bd4\u5982\u4f60\u628a\u4e00\u4e2abody\u7684\u5b50\u5143\u7d20\u505a\u4e86\u4fee\u6539\uff0c\u4e0d\u4e00\u5b9a\u4f1a\u5bfc\u81f4\u5927\u91cf\u7684\u5176\u4ed6\u8282\u70b9\u66f4\u65b0\uff0c\u4f46\u662f\u4f60\u628a\u4e00\u4e2a\u5143\u7d20\u79fb\u52a8\u5230\u9875\u9762\u9876\u90e8\u53bb\uff0c\u53ef\u80fd\u5c31\u4f1a\u5bfc\u81f4\u5168\u90e8\u5176\u4ed6\u8282\u70b9\u8fdb\u884c\u91cd\u6392\u64cd\u4f5c\uff0c\u8fd9\u4e2a\u4ee3\u4ef7\u5c31\u975e\u5e38\u6602\u8d35\u3002<\/p>\n
\u806a\u660e\u7684\u6d4f\u89c8\u5668<\/p>\n
\u56e0\u4e3a\u6e32\u67d3\u6811\u7684\u6539\u53d8\u5bfc\u81f4\u7684\u91cd\u7ed8\u6216\u91cd\u6392\u64cd\u4f5c\u90fd\u53ef\u80fd\u4ee3\u4ef7\u5f88\u9ad8\uff0c\u6d4f\u89c8\u5668\u4f1a\u5bf9\u8fd9\u4e2a\u6539\u52a8\u505a\u5f88\u591a\u4f18\u5316\u3002
\n\u4e00\u4e2a\u7b56\u7565\u5c31\u662f\u4e0d\u8981\u7acb\u5373\u505a\u64cd\u4f5c\uff0c\u800c\u662f\u6279\u91cf\u8fdb\u884c\u3002\u6bd4\u5982\u628a\u4f60\u7684\u811a\u672c\u5bf9DOM\u7684\u4fee\u6539\u653e\u5165\u4e00\u4e2a\u961f\u5217\uff0c\u5728\u961f\u5217\u6240\u6709\u64cd\u4f5c\u7ed3\u675f\u540e\u53ea\u9700\u8981\u8fdb\u884c\u4e00\u6b21\u7ed8\u5236\u5373\u53ef\u3002<\/p>\n
\u4f46\u662f\u6709\u7684\u65f6\u5019\u811a\u672c\u53ef\u80fd\u4f1a\u5bfc\u81f4\u6d4f\u89c8\u5668\u7684\u6279\u91cf\u4f18\u5316\u65e0\u6cd5\u8fdb\u884c\uff0c\u53ef\u80fd\u5728\u6e05\u7a7a\u961f\u5217\u4e4b\u524d\u5c31\u9700\u8981\u91cd\u65b0\u7ed8\u5236\uff08\u7ed8\u5236\u610f\u601d\u662f\u91cd\u7ed8\u6216\u8005\u91cd\u6392\uff09\u9875\u9762\u3002\u6bd4\u5982\u4f60\u901a\u8fc7\u811a\u672c\u83b7\u53d6\u8fd9\u4e9b\u6837\u5f0f\uff1a<\/p>\n
offsetTop, offsetLeft, offsetWidth, offsetHeight\r\nscrollTop\/Left\/Width\/Height\r\nclientTop\/Left\/Width\/Height\r\ngetComputedStyle(), or currentStyle in IE<\/pre>\n
\u56e0\u4e3a\u6d4f\u89c8\u5668\u5fc5\u987b\u7ed9\u4f60\u6700\u65b0\u7684\u503c\uff0c\u6240\u4ee5\u5f53\u4f60\u8fdb\u884c\u8fd9\u4e9b\u53d6\u503c\u64cd\u4f5c\u7684\u65f6\u5019\u4f1a\u7acb\u523b\u89e6\u53d1\u4e00\u6b21\u9875\u9762\u7684\u7ed8\u5236\u3002\u8fd9\u6837\u672c\u6765\u53ef\u4ee5\u6279\u91cf\u4fee\u6539\u6837\u5f0f\u7136\u540e\u4e00\u6b21\u6027\u7ed8\u5236\u7684\u65b9\u6cd5\u5c31\u65e0\u6cd5\u4f7f\u7528\u4e86\u3002<\/p>\n
\u51cf\u5c11\u91cd\u7ed8\u548c\u91cd\u6392<\/p>\n
1\uff0c\u4e0d\u8981\u4e00\u4e2a\u4e00\u4e2a\u5730\u5355\u72ec\u4fee\u6539\u5c5e\u6027\uff0c\u6700\u597d\u901a\u8fc7\u4e00\u4e2aclassname\u6765\u5b9a\u4e49\u8fd9\u4e9b\u4fee\u6539<\/p>\n
\/\/ bad
\nvar left = 10,
\ntop = 10;
\nel.style.left = left + “px”;
\nel.style.top\u00a0\u00a0= top\u00a0\u00a0+ “px”;<\/p>\n
\/\/ better
\nel.className += ” theclassname”;
\n2\uff0c\u628a\u5bf9\u8282\u70b9\u7684\u5927\u91cf\u4fee\u6539\u64cd\u4f5c\u653e\u5728\u9875\u9762\u4e4b\u5916
\n\u7528 documentFragment\u6765\u505a\u4fee\u6539
\nclone \u8282\u70b9\uff0c\u5728clone\u4e4b\u540e\u7684\u8282\u70b9\u4e2d\u505a\u4fee\u6539\uff0c\u7136\u540e\u76f4\u63a5\u66ff\u6362\u6389\u4ee5\u524d\u7684\u8282\u70b9
\n\u901a\u8fc7 display: none \u6765\u9690\u85cf\u8282\u70b9\uff08\u76f4\u63a5\u5bfc\u81f4\u4e00\u6b21\u91cd\u6392\u548c\u91cd\u7ed8\uff09\uff0c\u505a\u5927\u91cf\u7684\u4fee\u6539\uff0c\u7136\u540e\u663e\u793a\u8282\u70b9\uff08\u53c8\u4e00\u6b21\u91cd\u6392\u548c\u91cd\u7ed8\uff09\uff0c\u603b\u5171\u53ea\u4f1a\u6709\u4e24\u6b21\u91cd\u6392\u3002
\n3\uff0c\u4e0d\u8981\u9891\u7e41\u83b7\u53d6\u8ba1\u7b97\u540e\u7684\u6837\u5f0f\u3002\u5982\u679c\u4f60\u9700\u8981\u4f7f\u7528\u8ba1\u7b97\u540e\u7684\u6837\u5f0f\uff0c\u6700\u597d\u6682\u5b58\u8d77\u6765\u800c\u4e0d\u662f\u76f4\u63a5\u4eceDOM\u4e0a\u8bfb\u53d6\u3002<\/p>\n
4\uff0c\u603b\u7684\u6765\u8bf4\uff0c\u603b\u662f\u8003\u8651\u5230\u6e32\u67d3\u6811\u5f97\u5b58\u5728\uff0c\u8003\u8651\u5230\u4f60\u7684\u4e00\u6b21\u4fee\u6539\u4f1a\u5bfc\u81f4\u591a\u5927\u7684\u7ed8\u5236\u64cd\u4f5c\u3002
\n\u6bd4\u5982\u7edd\u5bf9\u5b9a\u4f4d\u5143\u7d20\u7684\u52a8\u753b\u5c31\u4e0d\u4f1a\u5f71\u54cd\u5176\u4ed6\u5927\u90e8\u5206\u5143\u7d20\u3002<\/p>\n
\u6b22\u8fce\u5206\u4eab\u672c\u6587\uff0c\u8f6c\u8f7d\u8bf7\u4fdd\u7559\u51fa\u5904\uff1a\u524d\u7aefABC<\/a> » \u91cd\u6784\u4e0e\u91cd\u7ed8<\/a><\/p>","protected":false},"excerpt":{"rendered":"
\u6d4f\u89c8\u5668\u7684\u6e32\u67d3\u8fc7\u7a0b 1\uff0c\u6d4f\u89c8\u5668\u89e3\u6790html\u6e90\u7801\uff0c\u7136\u540e\u521b\u5efa\u4e00\u4e2a DOM\u6811\u3002 \u5728DOM\u6811\u4e2d\uff0c\u6bcf\u4e00\u4e2aHTML\u6807\u7b7e\u90fd\u6709\u4e00\u4e2a\u5bf9\u5e94\u7684\u8282\u70b9\uff0c\u5e76\u4e14\u6bcf\u4e00\u4e2a\u6587\u672c\u4e5f\u90fd\u4f1a\u6709\u4e00\u4e2a\u5bf9\u5e94\u7684\u6587\u672c\u8282\u70b9\u3002 DOM\u6811\u7684\u6839\u8282\u70b9\u5c31\u662f docum […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[169,215],"_links":{"self":[{"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/posts\/1555"}],"collection":[{"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1555"}],"version-history":[{"count":4,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/posts\/1555\/revisions"}],"predecessor-version":[{"id":1559,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=\/wp\/v2\/posts\/1555\/revisions\/1559"}],"wp:attachment":[{"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1555"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1555"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.qdabc.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1555"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}