{"id":2387,"date":"2012-05-11T22:32:05","date_gmt":"2012-05-11T14:32:05","guid":{"rendered":"http:\/\/www.zhangxinxu.com\/wordpress\/?p=2387"},"modified":"2018-01-02T01:28:52","modified_gmt":"2018-01-01T17:28:52","slug":"after-js-content-css3-media-queries","status":"publish","type":"post","link":"https:\/\/www.zhangxinxu.com\/wordpress\/2012\/05\/after-js-content-css3-media-queries\/","title":{"rendered":"\u4f2a\u7c7b+js\u5b9e\u73b0CSS3 media queries\u8de8\u754c\u51c6\u786e\u5224\u65ad"},"content":{"rendered":"

by zhangxinxu<\/a> from http:\/\/www.zhangxinxu.com<\/a>
\n\u672c\u6587\u5730\u5740\uff1ahttp:\/\/www.zhangxinxu.com\/wordpress\/?p=2387<\/a><\/p>\n

\u4e00\u3001\u5bb9\u6211\u5520\u53e8<\/h3>\n

\u6211\u4eec\u90fd\u77e5\u9053\uff0cCSS3 media queries<\/code>\u662f\u54cd\u5e94\u5e03\u5c40<\/a>\u5b9e\u73b0\u4e4b\u5229\u5668\u3002\u56fd\u5916\u5f88\u591a\u8457\u540d\u7684\u524d\u7aef\u7ad9\u70b9\uff0c\u5982css-tricks<\/a>, smashingmagazinegazine<\/a>\u7b49\u90fd\u91c7\u7528\u4e86\u54cd\u5e94\u5e03\u5c40\u3002<\/p>\n

\u867d\u7136\u56fd\u5185\u6b64\u6280\u672f\u5e94\u7528\u5c31\u50cf\u662f\u6253\u4e0d\u7740\u7684\u6253\u706b\u673a\uff0c\u6ca1\u6cd5\u8ddf\u5982\u706b\u5982\u837c\u7684\u6b27\u7f8e\u76f8\u6bd4\u3002\u4f46\u662f\uff0c\u6bd5\u7adf\u8d8b\u52bf\u662f\u5411\u524d\u53d1\u5c55\u7684\uff0c\u603b\u4f1a\u8fce\u6765\u904d\u5730\u5f00\u82b1\u7684\u65f6\u5019\uff0c\u53ea\u662f\u65f6\u95f4\u7684\u957f\u77ed\u800c\u5df2\u3002<\/p>\n

\u672c\u6587\u6240\u6d89\u53ca\u7684\u4e09\u4e2a\u5173\u952e\u6280\u672f\u70b9\uff0c\u4f2a\u7c7b(IE8+), js(getComputedStyle, IE9+)\u4ee5\u53camedia queries(IE9+)\u90fd\u9700\u8981\u73b0\u4ee3\u6d4f\u89c8\u5668\u7684\u652f\u6301\u3002\u56e0\u6b64\uff0c\u5982\u679c\u60a8\u4e0d\u662f\u505aHTML5\u5f00\u53d1\uff0c\u6216\u662f\u4ece\u4e8b\u7684\u662f\u9762\u5411\u5927\u4f17\u7684\u666e\u901aweb\u9875\u9762\uff0c\u672c\u6587\u5185\u5bb9\u6ca1\u6709\u4efb\u4f55\u5b9e\u7528\u4ef7\u503c\u3002\u6709\u5e2e\u52a9\u7684\uff0c\u4f30\u8ba1\u5c31\u662f\u62d3\u5bbd\u601d\u8def\uff0c\u589e\u957f\u773c\u754c\u4e86\u3002\u56e0\u6b64\uff0c\u672c\u6587\u5185\u5bb9\u5f88\u5feb\u5c31\u4f1a\u5f52\u4e8e\u6c89\u5bc2\uff0c\u6216\u8bb85\u5e74\u4e4b\u540e\uff0c\u67d0\u541b\u9634\u5dee\u9633\u9519\u8fdb\u5165\u6b64\u5904\uff0c\u53d1\u73b0\u6b64\u6587\uff0c\u4f1a\u4e0d\u7531\u5f97\u60ca\u53f9\u2014\u2014\u539f\u6765\u5f88\u591a\u5e74\u524d\u5c31\u6709\u4eba\u4ecb\u7ecd\u8fd9\u4e2a\u6280\u672f\u5566\uff01\u4f46\u662f\uff0c\u5386\u53f2\u7684\u53d1\u5c55\u4e0e\u63a8\u52a8\u5c11\u4e0d\u4e86\u90a3\u4e9b\u6e6e\u6ca1\u5728\u5386\u53f2\u4e2d\u7684\u5f00\u62d3\u8005\u3002<\/p>\n

media queries<\/code>\u53ef\u4ee5\u8ba9\u8bbe\u5907\u5728\u4e0d\u540c\u5c3a\u5bf8\u4e0b\u5e94\u7528\u4e0d\u540c\u7684CSS\u6837\u5f0f\u3001\u5e03\u5c40\u7b49\u3002\u4ee5\u9002\u5e94\u624b\u6301\u8bbe\u5907\u3001\u666e\u5c4f\u663e\u793a\u5668\u3001\u5bbd\u5c4f\u663e\u793a\u5668\uff0c\u4ee5\u53ca\u672a\u6765\u51b0\u7bb1\u4e0a\u7684\u8054\u7f51\u663e\u793a\u5668\uff0c\u6c7d\u8f66\u4e0a\u7684\u6570\u7801\u8bbe\u5907\u7b49\u3002\u7136\u540e\uff0c\u4ec5\u4ec5\u901a\u8fc7CSS\u505a\u5e03\u5c40\u53ef\u80fd\u65e0\u6cd5\u5e94\u5bf9\u6240\u6709\u7684\u4ea4\u4e92\u8bf7\u6c42\u3002<\/p>\n

\u4e3e\u4e2a\u7b80\u5355\u4f8b\u5b50\uff0c\u6211\u4eec\u6253\u5f00\u6d4f\u89c8\u5668\u53ef\u80fd\u5904\u4e8e\u975e\u6700\u5927\u5316\u72b6\u6001\uff0c\u6b64\u65f6\uff0c\u5982\u679c\u4f5c\u4e3a\u666e\u5c4f\u5904\u7406\uff0c\u52a0\u8f7d\u7684\u56fe\u7247\u53ef\u80fd\u5c31\u662f128*128\u7684\u5c0f\u5c3a\u5bf8\u56fe\u7247\u3002\u4f46\u662f\uff0c\u5f53\u6211\u4eec\u6700\u5927\u5316\u4ee5\u83b7\u5f97\u66f4\u597d\u9605\u8bfb\u4f53\u9a8c\u7684\u65f6\u5019\uff0c\u9700\u8981\u4f7f\u7528\u66f4\u5927\u5c3a\u5bf8\u7684\u56fe\u7247256*256, \u4f7f\u7528media queries<\/code>? \u62dc\u6258\uff0cCSS\u53ea\u80fd\u6539\u53d8\u5916\u5728\u7684\u5c3a\u5bf8\uff0c\u4f60\u96be\u9053\u89812\u500d\u5c3a\u5bf8\u62c9\u4f38\uff1f\u663e\u7136\uff0c\u66f4\u5408\u7406\u7684\u505a\u6cd5\u662f\u52a0\u8f7d256*256\u5c3a\u5bf8\u7684\u4e2d\u7b49\u5c3a\u5bf8\u56fe\u7247\u3002\u4ee5\u76ee\u524d\u7684\u6280\u672f\u800c\u8a00\uff0c\u4f30\u8ba1\u9664\u4e86\u4f7f\u7528JS\u4fee\u6539\u56fe\u7247src<\/code>\u5916\uff0c\u5f88\u96be\u6709\u5176\u4ed6\u66f4\u53ef\u7528\u7684\u65b9\u6cd5\u4e86\u3002<\/p>\n

OK, \u73b0\u5728\u95ee\u9898\u6765\u4e86\uff0c\u5982\u4f55\u8ba9JS\u7684\u4fee\u6539\u4e0eCSS\u5e03\u5c40\u6539\u53d8\u540c\u6b65\u5462\uff1f<\/p>\n

\u4e8c\u3001CSS\u4ea4\u4e92\u4e0eJS\u4ea4\u4e92\u540c\u6b65\u95ee\u9898<\/h3>\n

\u5982\u4f55\u8ba9CSS\u6837\u5f0f\u3001\u5e03\u5c40\u6539\u53d8\u7684\u65f6\u5019\uff0c\u540c\u65f6\u51c6\u786e\u89e6\u53d1JS\u7684\u4ea4\u4e92\u5462\uff1f<\/p>\n

\u65b9\u6cd5\u4e00\u3001\u76f4\u63a5\u5bbd\u5ea6\/\u9ad8\u5ea6\u503c\u5339\u914d<\/strong>
\n\u4f55\u610f\uff1fCSS3 media queries<\/code>\u8de8\u754c\u89e6\u53d1\u4e00\u822c\u90fd\u6709\u4e00\u4e2a\u5bbd\u5ea6\u6216\u9ad8\u5ea6\u503c\uff0c\u6216\u662fcolor(\u5f88\u5c11\u4f7f\u7528)\u3002\u4f8b\u5982\uff0c\u666e\u5c4f\u56fe\u7247\u5bbd\u5ea6128*128\uff0c\u53ef\u80fd\u5c31\u662f\u5982\u4e0bCSS\uff1a<\/p>\n

\n
@media screen and (max-width: 1024px) {\n    img {\n        width: 128px;\n        height: 128px;\n    }\n} <\/pre>\n<\/div>\n
\u610f\u601d\u5c31\u662fscreen(\u5c4f\u5e55)\u5bbd\u5ea6\u4e0d\u8d85\u8fc71024\u50cf\u7d20(max-width:1024px<\/code>)\u7684\u65f6\u5019\uff0c\u56fe\u7247\u5bbd\u5ea6\u662f128\u50cf\u7d20\uff0c\u9ad8\u5ea6\u4e5f\u662f128\u50cf\u7d20\u3002<\/p>\n
\u56e0\u6b64\uff0c\u6211\u4eec\u53ef\u80fd\u901a\u8fc7\u6d4f\u89c8\u5668\u7a97\u53e3\u5c3a\u5bf8\u6539\u53d8\u7684resize\u4e8b\u4ef6\u4e2d\u6355\u83b7\u6d4f\u89c8\u5668\u7a97\u53e3\u5c3a\u5bf8\uff0c\u4e0e1024\u5bf9\u6bd4\uff0c\u5982\u679c\u5c0f\u4e8e\u5219\u89e6\u53d1\u5bf9\u5e94\u7684\u666e\u5c4f\u4e8b\u4ef6\u5904\u7406\uff0c\u5927\u4e8e\uff0c\u5219\u5bbd\u5c4f\u5904\u7406\u3002<\/p>\n
\n
window.addEventListener(\"resize\", function() {\n    \/\/ window.innerWidth IE9+\u6d4f\u89c8\u5668\u652f\u6301<\/span>\n    if (window.innerWidth <= 1024) {\n        \/\/ \u666e\u5c4f\u5904\u7406<\/span>\n    } else {\n        \/\/\u5bbd\u5c4f\u5904\u7406<\/span>\n    }\n});<\/pre>\n<\/div>\n
\u786e\u5b9e\u662f\u7b80\u5355\u9ad8\u6548\u7684\u65b9\u6cd5\u3002\u4f46\u662f\uff0c\u4e5f\u662f\u6709\u4e0d\u8db3\u7684\u3002<\/p>\n
\u2460 \u53ef\u7ef4\u62a4\u6027<\/strong>
\n\u4e00\u4e2a\u8f7d\u4f53\u6240\u5bf9\u5e94\u7684\u6570\u503c\u662f\u4f1a\u7ecf\u5e38\u53d8\u7684\u3002\u4f8b\u5982\uff0c\u5c0f\u80d6\u4eca\u5929\u4f53\u91cd148\u65a4\uff0c\u660e\u5929\u559d\u78a7\u751f\u6e90\u5395\u6240\u6765\u56de\u51e0\u4e2a\u5c0f\u65f6\uff0c\u53ef\u80fd\u5c31\u53ea\u6709145\u65a4\u4e86\u3002\u540c\u6837\u7684\uff0c\u5bf9\u4e8e1024\u8fd9\u4e2a\u503c\uff0c\u53d8\u52a8\u7684\u51e0\u7387\u662f\u5f88\u5927\u7684\u3002\u53d8\u52a8\u5176\u5b9e\u6ca1\u4ec0\u4e48\uff0c\u9ebb\u70e6\u7684\u662f\u4e0b\u9762\u7684JS\u4e2d\u7684\u5224\u65ad\u7684\u6570\u503c\u4e0eCSS\u4e2d\u7684\u9650\u5236\u662f\u8981\u4e00\u81f4\u7684\u3002\u4e5f\u5c31\u662fCSS\u5bbd\u5ea6\u9608\u503c\u6539\u53d8\uff0cJS\u4e5f\u8981\u8ddf\u7740\u53d8\u3002\u663e\u7136\uff0c\u8fd9\u79cd\u9ad8\u8026\u5408\u589e\u52a0\u4e86\u540e\u671f\u7684\u7ef4\u62a4\u6210\u672c\u3002<\/p>\n
\u2461 \u5bbd\u5ea6\u7684\u8ba1\u7b97\u4e0e\u4e0d\u786e\u5b9a\u6027<\/strong>
\nwindow.innerWidth<\/code>\u8fd4\u56de\u7684\u662f\u7a97\u53e3\u5185\u90e8\u5bbd\u5ea6\uff08\u4e0d\u5305\u62ec\u6d4f\u89c8\u5668\u7684\u6846\u6846\uff09\uff0c\u5355\u4f4d\u662f\u50cf\u7d20\u3002\u4f46\u662f\uff0cwidth<\/code>\u5c5e\u6027\u7684\u5355\u4f4d\u5e76\u4e0d\u56fa\u5b9a\u3002\u6709\u4e9b\u7ad9\u70b9\uff0c\u53ef\u80fd\u4f7f\u7528em<\/code>, %<\/code>\u6216\u6700\u65b0\u7684vw<\/code>, rem<\/code>, in<\/code>\u7b49\uff08\u5b8c\u6574\u5355\u4f4d\u53c2\u89c1\u4e4b\u524d\u201cCSS\u957f\u5ea6\u503c\u53ca\u65f6\u95f4\u3001\u9891\u7387\u3001\u89d2\u5ea6\u5355\u4f4d<\/a>\u201d\u4e00\u6587\uff09\u3002<\/p>\n
\u800c\u8fd9\u4e9b\u5355\u4f4d\u7684\u5bbd\u5ea6\u8f6c\u6362\u6210px<\/code>\u5c31\u9700\u8981\u8ba1\u7b97\uff0c\u800c\u8fd9\u4e9b\u5355\u4f4d\u5f88\u591a\u662f\u76f8\u5bf9\u7684\uff0c\u4f8b\u5982em<\/code>\u662f\u4e0e\u5b57\u4f53\u5927\u5c0f\u76f8\u5173\u7684\uff0c\u5982\u679c\u7f51\u9875\u7684\u5b57\u4f53\u5927\u5c0f\u88ab\u7528\u6237\u624b\u52a8\u6539\u53d8\uff08\u89c6\u529b\u4e0d\u4f73\u7528\u6237\uff0c\u6216\u662f\u201cCtrl + \u52a0\u53f7\u201d\u7684\u8bef\u64cd\u4f5c\uff09\uff0c\u53ef\u80fd\u4f60\u4e4b\u524d\u6309\u716712\u50cf\u7d20\u6bd4\u4f8b\u7684\u5bbd\u5ea6\u8ba1\u7b97\u5c31\u4f1a\u4e0d\u51c6\u786e\u3002\u8fd9\u5c31\u662f\u5bbd\u5ea6\u8ba1\u7b97\u7684\u4e0d\u786e\u5b9a\u6027\u3002<\/p>\n
\u53ef\u89c1\uff0c\u6211\u4eec\u6709\u5fc5\u8981\u5bfb\u6c42\u66f4\u4f73\u7684\u540c\u6b65\u65b9\u6cd5\u3002\u4ec0\u4e48\u5462\uff0c\u5c31\u901a\u8fc7CSS\u672c\u8eab\uff01<\/p>\n
\u901a\u8fc7CSS\u672c\u8eab\uff1f<\/strong>
\n\u6bd4\u65b9\u8bf4\u5427\uff08\u867d\u7136\u8fd9\u4e2a\u4f8b\u5b50\u5b9e\u7528\u6027\u4e0d\u4f73\uff09\uff0c\u6211\u4eec\u901a\u8fc7media queries<\/code>\u8ba9\u56fe\u7247\u5bbd\u5ea6\u53d8\u6210128\u50cf\u7d20\uff0c\u5c31\u53ef\u4ee5\u901a\u8fc7\u68c0\u6d4b\u56fe\u7247\u5e94\u7528\u7684\u5bbd\u5ea6\u5224\u65ad\u5f53\u524d\u8bbe\u5907\u72b6\u6001\u3002<\/p>\n
\u5f53\u7136\uff0c\u8fd9\u91cc\u53ea\u662f\u4e3e\u4f8b\uff0c\u5176\u5b9e\u8fd9\u6bd4\u4e0a\u97621024px\u65b9\u6cd5\u66f4\u6413\uff0c\u56e0\u4e3a\uff0c\u7275\u626f\u5230\u5b9e\u9645\u6837\u5f0f\u7684CSS\u662f\u4f1a\u7ecf\u5e38\u53d8\u52a8\u7684\uff0cJS\u663e\u7136\u4e0d\u80fd\u4e0e\u4e4b\u9ad8\u8026\u5408\u3002<\/p>\n
\u90a3\u8be5\u5982\u4f55\u5e94\u7528\u5462\uff1f\u5f88\u7b80\u5355\uff0c\u5e94\u7528\u5728\u4e0d\u4f1a\u4f7f\u7528\u7684\u5143\u7d20\uff0c\u4e0d\u4f1a\u4ea7\u751f\u989d\u5916\u5f71\u54cd\u7684CSS\u5c5e\u6027\u3002\u4f8b\u5982\u5728<head><\/code>\u6807\u7b7e\u4e0a\u4f7f\u7528z-index<\/code>\u5c5e\u6027\uff08from Stephanie<\/a>\uff09\u3002<\/p>\n
\n
@media screen and (min-width: 45em) {\n    head {\n        z-index: 2;\n    }\n}<\/pre>\n<\/div>\n
\"\u96be\u8fc7\u4e0d\u8fc7\uff0c\u6839\u636eJeremy Keith<\/a>\u7684\u6d4b\u8bd5\uff0cWebkit\u6d4f\u89c8\u5668\u8c8c\u4f3c\u4e0d\u652f\u6301\uff0c\u5176\u8fd4\u56de\u7684z-index<\/code>\u503c\u662fauto<\/code>, \u4e0d\u662f\u6570\u503c2<\/code>. \u6211\u90a3\u70ed\u4e4e\u4e4e\u7684\u5c0f\u5fc3\u810f\uff0c\u77ac\u95f4\u51b0\u51bb\uff0c\u554a~~<\/p>\n
\u5e94\u7528\u5728<body><\/code>\u6807\u7b7e\u4e0a\u5230\u662f\u53ef\u4ee5\u7684\uff0c\u4e0d\u8fc7\uff0c\u7531\u4e8ebody\u6807\u7b7e\u66b4\u9732\u5728\u5916\uff0c\u53c2\u4e0eCSS\u5e03\u5c40\uff0c\u5982\u4f55\u5176\u8bbe\u7f6e\u4e86\u5b9a\u4f4d\u5c5e\u6027\uff08relative, absolute\u7b49\uff09\uff0cz-index<\/code>\u7acb\u9a6c\u52c3\u8d77\uff0c\u5982\u679c\u91cc\u9762\u5728\u5c42\u7ea7\u590d\u6742\u70b9\uff0c\u54e6\u5475\u5475\uff0c\u5144\u5f1f\u4f60\u628a\u59b9\u7684\u65f6\u95f4\u4f30\u8ba1\u8981\u966a\u4ee3\u7801\u54af\uff01<\/p>\n
\u4e0d\u8fc7\uff0c\u5bf9\u4e8e\u4e00\u822c\u7684\u9875\u9762\uff08\u4e0d\u662f\u7c7b\u4f3c\u6e38\u620f\u9875\u9762\uff0c\u5e7b\u706f\u7247\u9875\u9762\u7684\u9875\u9762\uff09\uff0c\u53ea\u6709\u67d0\u4e9b\u827a\u9ad8\u4eba\u624d\u6562\u5728body\u4e0a\u589e\u52a0\u5b9a\u4f4d\u5c5e\u6027\uff08\u8fdd\u80cc\u6700\u5c0f\u5316\u5f71\u54cd\u539f\u5219<\/a> – part 7\uff09\uff0c\u56e0\u6b64\uff0c\u5728body<\/code>\u4e0a\u8bbe\u7f6ez-index<\/code>\u5c5e\u6027\u4e00\u822c\u95ee\u9898\u4e0d\u5927\uff0c\u4f46\u662f\uff0c\u4ece\u53ef\u7406\u89e3\u6027\u4e0a\u8bb2\uff0cz-index<\/code>\u5f31\u4e86\u70b9\u3002\u56e0\u4e3a\uff0cz-index<\/code>\u503c\u4e00\u822c\u662f\u6570\u503c\u3002\u4f60\u8bf4\uff1a<\/p>\n
800~1024     z-index:1;\n1024~1280     z-index:2;\n1280~1440     z-index:3;\n1440~1680     z-index:4; <\/pre>\n
\u4e24\u4e2a\u6708\u540e\uff0c\u4f60\u5728\u770bJS\u4e2d\uff0czIndex<\/code>\u76841<\/code>, 2<\/code>, 3<\/code>, 4<\/code>\uff0c\u4f60\u8fd8\u8bb0\u5f97\u5bf9\u5e94\u7684\u6570\u503c\u8303\u56f4\u5417\uff1f\u522b\u4eba\u7ecf\u624b\u4f60\u7684\u4ee3\u7801\uff0c\u77e5\u9053\u5404\u4e2a\u6570\u503c\u5bf9\u5e94\u7684\u542b\u4e49\u5417\uff1f\uff08\u522b\u8ddf\u6211\u626f\u6ce8\u91ca~~\uff09<\/p>\n
\u56e0\u6b64\uff0c\u6211\u4eec\u9700\u8981\u5bfb\u6c42\u66f4\u4f73\u7684\u65b9\u6848\u3002<\/p>\n
\u65b9\u6cd5\u4e8c\u3001body\u6807\u7b7e+\u4f2a\u7c7b+content\u5185\u5bb9\u751f\u6210<\/strong>
\n\u56e0\u4e3a\u6bcf\u4e2a\u9875\u9762\u90fd\u6709body<\/code>\u6807\u7b7e\uff0c\u5728\u8be5\u6807\u7b7e\u4e0a\u6253\u6807\u8bb0\u4fbf\u4e8e\u6574\u7ad9\u901a\u7528\u3002<\/p>\n
\u8fd9\u91cc\u7684\u4f2a\u7c7b\u6307:after<\/code>, :before<\/code>\u4ea6\u53ef\uff0c\u56e0\u4e3a\uff0c\u4f7f\u7528\u8be5CSS\u5c5e\u6027\u4e0e\u5b9e\u9645\u7528\u9014\u51b2\u7a81\u6982\u7387\u8981\u6bd4z-index<\/code>\u5c5e\u6027\u5c0f\u591a\u4e86\uff0c\u66f4\u52a0\u5b89\u5168\u3002<\/p>\n
content\u5185\u5bb9\u751f\u6210\u6211\u4e13\u95e8\u5199\u8fc7\u4e00\u7bc7\u6587\u7ae0\uff1a\u201cCSS content\u5185\u5bb9\u751f\u6210\u6280\u672f\u4ee5\u53ca\u5e94\u7528<\/a>\u201d\uff0c\u540e\u6765\u53c8\u7ed3\u679c\u4f2a\u7c7b\u5c5e\u6027\u5199\u4e86\u7bc7\uff1a\u201c:after\u4f2a\u7c7b+content\u5185\u5bb9\u751f\u6210\u7ecf\u5178\u5e94\u7528<\/a>\u201d\u3002\u60a8\u6709\u5174\u8da3\u53ef\u4ee5\u770b\u770b\u3002\u800c\u8fd9\u91cc\uff0c\u5219\u662f\u4e00\u4e2a\u65b0\u7684\u5e94\u7528\u5178\u578b\u4e86\u3002<\/p>\n
\u4f7f\u7528content\u5185\u5bb9\u751f\u6210\u7684\u6700\u5927\u597d\u5904\u5728\u4e8e\uff0c\u6211\u4eec\u53ef\u4ee5\u968f\u610f\u5b9a\u4e49\u91cc\u9762\u7684\u5185\u5bb9\uff08z-index\u53ea\u80fd\u6570\u503c\uff09\uff0c\u4f8b\u5982\uff1a<\/p>\n
\n
{ content: \"\u666e\u5c4f\"; }<\/pre>\n<\/div>\n
\u663e\u7136\uff0c\u8fd9\u4e2a\u63cf\u8ff0\u6027\u7684\u6587\u5b57\u662f\u5f88\u6cdb\u7684\uff0c\u6982\u62ec\u6027\u5f3a\uff0c\u4e0d\u4f1a\u56e0\u4e3a1024px<\/code>\u53d8\u6210980px<\/code>\u800c\u8ddf\u7740\u53d8\u52a8\uff0c\u800c\u4e14\uff0c\u542b\u4e49\u660e\u663e\uff0c\u4e00\u76ee\u4e86\u7136\u3002<\/p>\n
\u56e0\u6b64\uff0c\u4e0a\u9762\u7684\u4e00\u756a\u5206\u6790\u603b\u7ed3\uff0cbody:after + content<\/code>\u662f\u76f8\u5f53\u597d\u7684\u4e00\u4e2a\u65b9\u6cd5\u3002<\/p>\n
\u6211\u4eec\u552f\u4e00\u5269\u4e0b\u7684\u6280\u672f\u96be\u70b9\u5c31\u662f\u5982\u4f55\u4f7f\u7528JS\u83b7\u53d6content<\/code>\u7684\u5185\u5bb9\u3002\u5f53\u5f53\u5f53\u5f53\uff0c\u524d\u51e0\u5929\u7684\u5199\u7684\u201c\u83b7\u53d6\u5143\u7d20CSS\u503c\u4e4bgetComputedStyle\u65b9\u6cd5\u719f\u6089<\/a>\u201d\u4e00\u6587\u5185\u5bb9\u5c31\u6d3e\u4e0a\u7528\u573a\u4e86\u3002<\/p>\n
\u4f7f\u7528\u65b9\u6cd5\u5c31\u662f\u6807\u9898\u4e2d\u7684getComputedStyle<\/code>:<\/p>\n
\n
var content = window.getComputedStyle(document.body, \":after\").getPropertyValue(\"content\");<\/pre>\n<\/div>\n
\u7136\u540e\uff0c\u6211\u4eec\u5c31\u53ef\u4ee5\u6839\u636econtent<\/code>\u7684\u5177\u4f53\u5185\u5bb9\uff0c\u51c6\u786e\u6355\u83b7media queries\u8d8a\u754c\u7684\u77ac\u95f4\uff0c\u5e76\u4f5c\u51fa\u76f8\u5173\u7684JS\u4ea4\u4e92\u4e86\uff01<\/p>\n
\n
if (content === \"\u7a84\u5c4f\") {\n    \/\/ \u2026\u2026<\/span>\n} else if (content === \"\u666e\u5c4f\") {\n    \/\/ \u2026\u2026<\/span>\n} else if (content === \"\u5bbd\u5c4f\") {\n    \/\/ \u2026\u2026<\/span>\n}\n<\/pre>\n<\/div>\n
\u4e09\u3001\u767e\u95fb\u4e0d\u5982\u4e00\u89c1<\/h3>\n
\u60a8\u53ef\u4ee5\u72e0\u72e0\u5730\u70b9\u51fb\u8fd9\u91cc\uff1a\u4f2a\u7c7b+js\u4e0emedia queries\u8de8\u754cdemo<\/a><\/p>\n
\u4e0b\u56fe\u4e3a\u5bbd\u5c4f(1680px<\/code>)\u4e0b\u7b49\u6bd4\u7f29\u653e\u7684\u6548\u679c\u56fe\uff1a
\n\"\u5bbd\u5c4f\u4e0b\u56fe\u7247\u7684\u663e\u793a\"<\/p>\n
\u6211\u4eec\u4fee\u5728\u5bbd\u5ea6\u6539\u62101024px<\/code>\uff0c\u5219\u56fe\u7247\u4e0d\u4ec5\u5c3a\u5bf8\u53d8\u5c0f\u4e86\uff0csrc\u5730\u5740\u4e5f\u5e94\u7528\u4e86\u5c0f\u56fe\u7684\u5730\u5740\uff1a
\n\"\"
\n\"\"<\/p>\n
\u76f8\u5173CSS\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
\n
.demo img {\n    width: 512px;\n}\n@media screen and (max-width: 1024px) {\n    body:after {\n        display: none;\n        content: 'normalscreen';\n    }\n    .demo img {\n        width: 256px;\n    }\n}<\/pre>\n<\/div>\n
JS\u4ee3\u7801\u6bd4\u8f83\u957f\uff0c\u8fd9\u91cc\u5c31\u4e0d\u5b8c\u6574\u5c55\u793a\u4e86\uff0c\u4e0d\u8fc7\u6709\u4e2a\u4e1c\u897f\u5f88\u91cd\u8981\uff0c\u9700\u8981\u63d0\u9192<\/strong>\u4e0b\uff1a
\ngetComputedStyle<\/code>\u8fd4\u56de\u7684content<\/code>\u503c\u5728\u67d0\u4e9b\u6d4f\u89c8\u5668\u4e0b\u662f\u5e26\u6709\u5f15\u53f7\u7684\uff0c\u56e0\u6b64\uff0c\u4f60\u4e0d\u80fd\u4f7f\u7528===<\/code>\u76f4\u63a5\u5339\u914d\uff0c\u53ef\u4ee5\u4f7f\u7528\u7b80\u5355\u6b63\u5219test<\/code>\u65b9\u6cd5\uff08demo\u9875\u9762\u7684\u65b9\u6cd5\uff09\uff0c\u6216\u662f\u7d22\u5f15\u67e5\u627eindexOf<\/code>\u65b9\u6cd5\uff0c\u6216\u662f\u5b57\u7b26\u5206\u9694split<\/code>\u65b9\u6cd5\u7b49\u3002<\/p>\n
\n
\nif (content === \"normalscreen\") {}<\/del>\n\nif (\/normalscreen\/.test(content)) {}\n<\/pre>\n<\/div>\n
\u56db\u3001\u6211\u809a\u5b50\u5f88\u997f<\/h3>\n
\u4e0a\u5348\u9a7e\u9a76\u5458\u8003\u8bd5\uff0c\u8003\u6869\u8003\u548c\u5c0f\u8def\uff0c\u8bf7\u5047\u4e86\uff0c\u4e0b\u5348\u624d\u56de\u6765\u3002\u4e8e\u662f\uff0c\u665a\u4e0a\u5fd9\u7740\u8d76\u6d3b\uff0c\u5b8c\u6210\u672c\u6587\uff0c\u665a\u996d\u4e5f\u61d2\u5f97\u5403\uff0c\u56e0\u6b64\uff0c\u73b0\u5728\u8fd8\u997f\u7740\u3002\u672c\u6765\u60f3\u8865\u4e00\u4e2amedia queries<\/code>\u4e0etransition<\/code>\u52a8\u753b\u914d\u5408\uff0c\u4f7f\u7528JS\u505a\u54cd\u5e94\u5ef6\u8fdf\u7684\u4f8b\u5b50\uff08\u8de8\u754c\u7684\u65f6\u5019\uff0c\u5e94\u7528\u4e86transition<\/code>\u7684\u5143\u7d20\u52a8\u753b\uff0c\u6b64\u65f6\uff0c\u5373\u65f6\u54cd\u5e94\u7684JS\u4ea4\u4e92\u53ef\u80fd\u5c31\u4f1a\u51fa\u95ee\u9898\uff0c\u5982\u5b9a\u4f4d\u7b49\uff09\u3002<\/p>\n
\u4e0d\u8fc7\uff0c\u809a\u5b50\u997f\u997f\uff0c\u5c31\u61d2\u5f97\u641e\u4e86\u3002\u597d\uff0c\u6211\u8981\u8d76\u5feb\u64a4\u4e86\uff0c\u53bb\u5403\u897f\u5317\u53e3\u5473\u7684\u201c\u8304\u5b50\u725b\u8089\u76d6\u6d47\u996d\u201d\uff0c\u6211\u53e3\u6c34\u4e0b\u6765\u54af~~
\n\"\u53e3\u6c34<\/p>\n
\u672c\u6587\u4e3a\u539f\u521b\u6587\u7ae0\uff0c\u8f6c\u8f7d\u8bf7\u6ce8\u660e\u6765\u81ea\u5f20\u946b\u65ed-\u946b\u7a7a\u95f4-\u946b\u751f\u6d3b<\/a>[http:\/\/www.zhangxinxu.com<\/a>]
\n\u672c\u6587\u5730\u5740\uff1ahttp:\/\/www.zhangxinxu.com\/wordpress\/?p=2387<\/a><\/p>\n
\uff08\u672c\u7bc7\u5b8c\uff09<\/p>\n","protected":false},"excerpt":{"rendered":"
\u6211\u4eec\u90fd\u77e5\u9053\uff0cCSS3 media queries\u662f\u54cd\u5e94\u5e03\u5c40\u5b9e\u73b0\u4e4b\u5229\u5668\u3002\u56fd\u5916\u5f88\u591a\u8457\u540d\u7684\u524d\u7aef\u7ad9\u70b9\uff0c\u5982css-tricks, smashingmagazinegazine\u7b49\u90fd\u91c7\u7528\u4e86\u54cd\u5e94\u5e03\u5c40\u3002
\n\u867d\u7136\u56fd\u5185\u6b64\u6280\u672f\u5e94\u7528\u5c31\u50cf\u662f\u6253\u4e0d\u7740\u7684\u6253\u706b\u673a\uff0c\u6ca1\u6cd5\u8ddf\u5982\u706b\u5982\u837c\u7684\u6b27\u7f8e\u76f8\u6bd4\u3002\u4f46\u662f\uff0c\u6bd5\u7adf\u8d8b\u52bf\u662f\u5411\u524d\u53d1\u5c55\u7684\uff0c\u603b\u4f1a\u8fce\u6765\u904d\u5730\u5f00\u82b1\u7684\u65f6\u5019\uff0c\u53ea\u662f\u65f6\u95f4\u7684\u957f\u77ed\u800c\u5df2\u3002
\nmedia queries\u53ef\u4ee5\u8ba9\u8bbe\u5907\u5728\u4e0d\u540c\u5c3a\u5bf8\u4e0b\u5e94\u7528\u4e0d\u540c\u7684CSS\u6837\u5f0f\u3001\u5e03\u5c40\u7b49\u3002\u4ee5\u9002\u5e94\u624b\u6301\u8bbe\u5907\u3001\u666e\u5c4f\u663e\u793a\u5668\u3001\u5bbd\u5c4f\u663e\u793a\u5668\uff0c\u4ee5\u53ca\u672a\u6765\u51b0\u7bb1\u4e0a\u7684\u8054\u7f51\u663e\u793a\u5668\uff0c\u6c7d\u8f66\u4e0a\u7684\u6570\u7801\u8bbe\u5907\u7b49\u3002\u7136\u540e\uff0c\u4ec5\u4ec5\u901a\u8fc7CSS\u505a\u5e03\u5c40\u53ef\u80fd\u65e0\u6cd5\u5e94\u5bf9\u6240\u6709\u7684\u4ea4\u4e92\u8bf7\u6c42\u3002
\n\u2026\u2026
\n\u5982\u4f55\u8ba9JS\u7684\u4fee\u6539\u4e0eCSS\u5e03\u5c40\u6539\u53d8\u540c\u6b65\u5462\uff1f<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[180],"tags":[319,365,386,62,714,498,288,640],"_links":{"self":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/2387"}],"collection":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/comments?post=2387"}],"version-history":[{"count":0,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/2387\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/media?parent=2387"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/categories?post=2387"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/tags?post=2387"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}