{"id":2568,"date":"2012-08-23T15:56:39","date_gmt":"2012-08-23T07:56:39","guid":{"rendered":"http:\/\/www.zhangxinxu.com\/wordpress\/?p=2568"},"modified":"2018-01-02T01:51:51","modified_gmt":"2018-01-01T17:51:51","slug":"window-devicepixelratio","status":"publish","type":"post","link":"https:\/\/www.zhangxinxu.com\/wordpress\/2012\/08\/window-devicepixelratio\/","title":{"rendered":"\u8bbe\u5907\u50cf\u7d20\u6bd4devicePixelRatio\u7b80\u5355\u4ecb\u7ecd"},"content":{"rendered":"<p>by <a href=\"http:\/\/www.zhangxinxu.com\/\">zhangxinxu<\/a> from <a href=\"http:\/\/www.zhangxinxu.com\/\">http:\/\/www.zhangxinxu.com<\/a><br \/>\n\u672c\u6587\u5730\u5740\uff1a<a href=\"http:\/\/www.zhangxinxu.com\/wordpress\/?p=2568\">http:\/\/www.zhangxinxu.com\/wordpress\/?p=2568<\/a><\/p>\n<p>\u672c\u6587\u6240\u8bf4<code>devicePixelRatio<\/code>\u5176\u5b9e\u6307\u7684\u662f<code>window.devicePixelRatio<\/code>, \u88ab\u6240\u6709WebKit\u6d4f\u89c8\u5668\u4ee5\u53caOpera\u6240\u652f\u6301\uff0c\u968f\u7740\u663e\u793a\u5668\u7684\u53d1\u5c55\uff0c\u8fd9\u4e2a\u5c5e\u6027\u4e5f\u6162\u6162\u767b\u4e0a\u4e86\u524d\u7aef\u6280\u672f\u7684\u821e\u53f0\u3002<\/p>\n<p>\u672c\u6587\u5185\u5bb9\u5927\u90e8\u5206\u5c5e\u4e8e\u7ffb\u8bd1\u6027\u8d28\u5185\u5bb9\uff0c\u56e0\u6b64\uff0c\u4f1a\u4e0d\u90a3\u4e48\u901a\u4fd7\u6613\u61c2\u3002\u4e0d\u8fc7\uff0c\u4f60\u662f\u505a\u624b\u673a\u5f00\u53d1\u7684\uff0c\u6216\u662f\u6709\u610f\u5411\u7684\uff0c\u672c\u6587\u7684\u5185\u5bb9\u5982\u679c\u7ec6\u7ec6\u8bfb\u6765\uff0c\u8fd8\u662f\u6709\u4e9b\u6536\u83b7\u7684\u3002<\/p>\n<h3>\u4e00\u3001\u5b9a\u4e49<\/h3>\n<p>\u5b9a\u4e49\u5982\u4e0b\uff1a<\/p>\n<blockquote><p>window.devicePixelRatio\u662f\u8bbe\u5907\u4e0a\u7269\u7406\u50cf\u7d20\u548c\u8bbe\u5907\u72ec\u7acb\u50cf\u7d20(device-independent pixels (dips))\u7684\u6bd4\u4f8b\u3002<br \/>\n\u516c\u5f0f\u8868\u793a\u5c31\u662f\uff1awindow.devicePixelRatio = \u7269\u7406\u50cf\u7d20 \/ dips<\/p><\/blockquote>\n<p>dip\u6216dp,\uff08device independent pixels\uff0c\u8bbe\u5907\u72ec\u7acb\u50cf\u7d20\uff09\u4e0e\u5c4f\u5e55\u5bc6\u5ea6\u6709\u5173\u3002dip\u53ef\u4ee5\u7528\u6765\u8f85\u52a9\u533a\u5206\u89c6\u7f51\u819c\u8bbe\u5907\u8fd8\u662f\u975e\u89c6\u7f51\u819c\u8bbe\u5907\u3002<\/p>\n<p>\u6240\u6709\u975e\u89c6\u7f51\u819c\u5c4f\u5e55\u7684iphone\u5728\u5782\u76f4\u7684\u65f6\u5019\uff0c\u5bbd\u5ea6\u4e3a320\u7269\u7406\u50cf\u7d20\u3002\u5f53\u4f60\u4f7f\u7528<code>&lt;meta name=\"viewport\" content=\"width=device-width\"&gt;<\/code>\u7684\u65f6\u5019\uff0c\u4f1a\u8bbe\u7f6e\u89c6\u7a97\u5e03\u5c40\u5bbd\u5ea6\uff08\u4e0d\u540c\u4e8e\u89c6\u89c9\u533a\u57df\u5bbd\u5ea6\uff0c\u4e0d\u653e\u5927\u663e\u793a\u60c5\u51b5\u4e0b\uff0c\u4e24\u8005\u5927\u5c0f\u4e00\u81f4\uff0c\u89c1\u4e0b\u56fe\uff09\u4e3a320px, \u4e8e\u662f\uff0c\u9875\u9762\u5f88\u81ea\u7136\u5730\u8986\u76d6\u5728\u5c4f\u5e55\u4e0a\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" alt=\"\u5e03\u5c40\u89c6\u56fe\u5927\u5c0f \u5f20\u946b\u65ed-\u946b\u7a7a\u95f4-\u946b\u751f\u6d3b\" src=\"http:\/\/image.zhangxinxu.com\/image\/blog\/201208\/mobile_viewportzoomedout.jpg\" title=\"\u5e03\u5c40\u89c6\u56fe\u5927\u5c0f \u5f20\u946b\u65ed-\u946b\u7a7a\u95f4-\u946b\u751f\u6d3b\" class=\"alignnone\" width=\"229\" height=\"402\" \/><\/p>\n<p>\u8fd9\u6837\uff0c\u975e\u89c6\u7f51\u819c\u5c4f\u5e55\u7684iphone\u4e0a\uff0c\u5c4f\u5e55\u7269\u7406\u50cf\u7d20320\u50cf\u7d20\uff0c\u72ec\u7acb\u50cf\u7d20\u4e5f\u662f320\u50cf\u7d20\uff0c\u56e0\u6b64\uff0c<code>window.devicePixelRatio<\/code>\u7b49\u4e8e<code>1<\/code>.<\/p>\n<p>\u800c\u5bf9\u4e8e\u89c6\u7f51\u819c\u5c4f\u5e55\u7684iphone\uff0c\u5982iphone4s, \u7eb5\u5411\u663e\u793a\u7684\u65f6\u5019\uff0c\u5c4f\u5e55\u7269\u7406\u50cf\u7d20640\u50cf\u7d20\u3002\u540c\u6837\uff0c\u5f53\u7528\u6237\u8bbe\u7f6e<code>&lt;meta name=\"viewport\" content=\"width=device-width\"&gt;<\/code>\u7684\u65f6\u5019\uff0c\u5176\u89c6\u533a\u5bbd\u5ea6\u5e76\u4e0d\u662f640\u50cf\u7d20\uff0c\u800c\u662f320\u50cf\u7d20\uff0c\u8fd9\u662f\u4e3a\u4e86\u6709\u66f4\u597d\u7684\u9605\u8bfb\u4f53\u9a8c &#8211; \u66f4\u5408\u9002\u7684\u6587\u5b57\u5927\u5c0f\u3002<\/p>\n<p>\u8fd9\u6837\uff0c\u5728\u89c6\u7f51\u819c\u5c4f\u5e55\u7684iphone\u4e0a\uff0c\u5c4f\u5e55\u7269\u7406\u50cf\u7d20640\u50cf\u7d20\uff0c\u72ec\u7acb\u50cf\u7d20\u8fd8\u662f320\u50cf\u7d20\uff0c\u56e0\u6b64\uff0c<code>window.devicePixelRatio<\/code>\u7b49\u4e8e<code>2<\/code>.<\/p>\n<h3>\u4e8c\u3001\u6d4f\u89c8\u5668\u652f\u6301<\/h3>\n<ul>\n<li>IE\u4ee5\u53caFireFox\u538b\u6839\u4e0d\u652f\u6301\u3002\u53ef\u80fd\u63a5\u4e0b\u6765\u7684\u7248\u672c\u4f1a\u652f\u6301\u3002<\/li>\n<li>Opera\u684c\u9762\u6d4f\u89c8\u5668\u65f6\uff0c\u5373\u4f7f\u662f\u89c6\u7f51\u819c\u8bbe\u5907\uff0c\u8fd4\u56de\u7684\u503c\u4e5f\u662f1\u800c\u4e0d\u662f2. \u4e0d\u8fc7\uff0c\u8fd9\u4e2abug\u5728\u540e\u7eed\u7684\u7248\u672c\u4e2d\u4f1a\u4fee\u590d\u7684\u3002<\/li>\n<li>Opera Mobile 10\u4e0d\u652f\u6301\uff0c\u4e0d\u8fc7Opera Mobile 12\u6b63\u786e\u652f\u6301\u3002<\/li>\n<li>UC\u603b\u662f\u663e\u793a1\uff0c\u4e0d\u8fc7\u5176viewport\u5c5e\u6027\u6709\u4e9b\u8ba9\u4eba\u8d39\u89e3\u3002<\/li>\n<li>\u53ea\u6709\u6700\u8fd1\u7684Chrome\u6d4f\u89c8\u5668\u624d\u80fd\u6b63\u786e\u5b9e\u73b0\u8be5\u5c5e\u6027\u3002Chrome19\u8fd4\u56de\u4e0d\u51c6\u786e\u76841, Chrome22\u53ef\u4ee5\u6b63\u786e\u8fd4\u56de2.<\/li>\n<li>MeeGo WebKit (Nokia N9\/N950)\u5c31\u5413\u4eba\u4e86\uff1a\u5f53\u4f60\u5e94\u7528\u4e86meta viewport\u65f6\u5019\uff08\u7c7b\u4f3c<code>&lt;meta name=\"viewport\" content=\"width=device-width\"&gt;<\/code>\uff09\uff0c\u503c\u4f1a\u4ece1\u53d8\u62101.5!<\/li>\n<\/ul>\n<p>\u771f\u662f\u559c\u5fe7\u53c2\u534a\u3002\u597d\u7684\u662fSafari, Android WebKit, Chrome 22+(Android), Opera Mobile, BlackBerry WebKit, QQ, Palm WebKit, \u53caDolfin\u90fd\u80fd\u6b63\u786e\u5b9e\u73b0\u8be5\u5c5e\u6027\u3002<\/p>\n<p>\u5f53\u7136\uff0c\u5927\u90e8\u5206\u8fd9\u4e9b\u6d4f\u89c8\u5668\u4ecd\u7136\u8fd0\u884c\u5728<code>devicePixelRatio<\/code>\u503c\u5e94\u8be5\u4e3a<code>1<\/code>\u7684\u7cfb\u7edf\u4e0a\uff0c\u5f53\u5b83\u4eec\u79fb\u52a8\u5230\u89c6\u7f51\u819c\u7c7b\u4f3c\u8bbe\u5907\u65f6\u5019\uff0c\u53ef\u80fd\u5c31\u4f1a\u9047\u5230\u95ee\u9898\u3002<\/p>\n<p>\u4e24\u4e2a\u6ce8\u610f\u4e8b\u9879\uff1a<br \/>\nMeeGo WebKit <code>meta viewport<\/code>\u5e94\u7528\u65f6\u6539\u53d8\u503c\u7684\u505a\u6cd5\u662f\u5927\u9519\u7279\u9519\u7684\u3002\u8bbe\u5907\u50cf\u7d20\u6bd4\u5e94\u8be5\u662f\u4e0d\u53d8\u7684\uff0c\u4e0d\u4ec5\u7269\u7406\u50cf\u7d20\u503c\uff0c\u8bbe\u5907\u72ec\u7acb\u50cf\u7d20\u4e5f\u662f\u5982\u6b64\u3002<\/p>\n<p>\u4e8c\u662f\uff0c\u4e00\u4e9b\u6d4f\u89c8\u5668\u4e60\u60ef\u5728<code>meta viewport<\/code>\u5e94\u7528\u65f6\u6539\u53d8\u5404\u79cd\u4e1c\u897f\uff08\u4e09\u661f\u7684Dolfin\u5c31\u662f\u4ee3\u8868\uff09\uff0c\u8fd9\u5b8c\u5168\u5c31\u662f\u5728\u778e\u641e\u3002\u552f\u4e00\u7684\u53d8\u5316\u5e94\u8be5\u662f\u5e03\u5c40\u89c6\u56fe\u7684\u5c3a\u5bf8\u3002\u5982\u679c\u6d4f\u89c8\u5668\u53d8\u4e86\u5176\u4ed6\u4ec0\u4e48\u90fd\u662f\uff0c\u90a3\u90fd\u662f\u5f88\u632b\u7684\u3002<\/p>\n<p><strong>\u5b9e\u9645\u6d4b\u8bd5<\/strong><br \/>\n\u60a8\u53ef\u4ee5\u72e0\u72e0\u5730\u70b9\u51fb\u8fd9\u91cc\uff1a<a class=\"a_link\" target=\"_blank\" href=\"http:\/\/www.zhangxinxu.com\/study\/201208\/window-device-pixel-ratio.html\">window.devicePixelRatio\u503c\u652f\u6301\u4e0e\u5426\u6d4b\u8bd5demo<\/a><\/p>\n<p>\u4f8b\u5982\uff0c\u6211\u73b0\u5728\u7684FireFox\u684c\u9762\u7248(14.0.1)\u5f39\u51fa\u7684\u5c31\u662f<code>undefined<\/code>, \u5982\u4e0b\u56fe\uff1a<br \/>\n<img loading=\"lazy\" decoding=\"async\" alt=\"FireFox\u4e0d\u652f\u6301devicePixelRatio\u7ed3\u679c\u622a\u56fe \u5f20\u946b\u65ed-\u946b\u7a7a\u95f4-\u946b\u751f\u6d3b\" src=\"http:\/\/image.zhangxinxu.com\/image\/blog\/201208\/2012-08-23_140354.png\" title=\"FireFox\u4e0d\u652f\u6301devicePixelRatio\u7ed3\u679c\u622a\u56fe\" class=\"alignnone\" width=\"280\" height=\"186\" \/><\/p>\n<p>Chrome\u4e0b\u662f\u8ba4\u8bc6\u8fd9\u4e2a\u5c5e\u6027\u7684\uff0c\u5728\u6211\u673a\u5b50\u4e0a\u5f39\u51fa\u7684\u662f<code>1<\/code>, \u5982\u4e0b\u56fe\uff1a<br \/>\n<img loading=\"lazy\" decoding=\"async\" alt=\"Chrome\u6d4f\u89c8\u5668\u4e0bdevicePixelRatio\u5f39\u51fa\u7ed3\u679c\u622a\u56fe \u5f20\u946b\u65ed-\u946b\u7a7a\u95f4-\u946b\u751f\u6d3b\" src=\"http:\/\/image.zhangxinxu.com\/image\/blog\/201208\/2012-08-23_140751.png\" title=\"Chrome\u6d4f\u89c8\u5668\u4e0bdevicePixelRatio\u5f39\u51fa\u7ed3\u679c\u622a\u56fe \u5f20\u946b\u65ed-\u946b\u7a7a\u95f4-\u946b\u751f\u6d3b\" class=\"alignnone\" width=\"396\" height=\"171\" \/><\/p>\n<h3>\u5176\u4ed6\u4e00\u4e9b\u7cfb\u7edf\u3001\u8bbe\u5907<\/h3>\n<p><strong>1. iOS<\/strong><br \/>\n\u7c7b\u4f3c\u7684\uff0c\u65e0\u89c6\u7f51\u819c\u8bbe\u5907<code>devicePixelRatio<\/code>\u503c\u4e3a<code>1<\/code>\uff0c\u89c6\u7f51\u819c\u8bbe\u5907\u4e3a<code>2<\/code>. \u56e0\u4e3a\u5b9e\u9645\u7684\u50cf\u7d20\u4e2a\u6570\u662f\u53cc\u500d\u3002\u4e0d\u8fc7\uff0ciphone\u4f3c\u4e4e\u4e0d\u613f\u610f\u6539\u53d8\u5927\u5bb6\u90fd\u719f\u77e5\u4e60\u60ef\u7684320\u50cf\u7d20\u5bbd\u5ea6\u5e03\u5c40\uff0c\u6ca1\u6709\u628a\u8bbe\u5907\u5bbd\u5ea6\u4e00\u4e0b\u5b50\u53d8\u6210640\u50cf\u7d20\uff0c\u56e0\u6b64\uff0cdips\u5bbd\u5ea6\u4f9d\u7136\u662f320, \u4e8e\u662f<code>devicePixelRatio<\/code>\u5c31\u662f<code>640\/320 = 2<\/code>.<\/p>\n<p>iOS\u4e0a\u7684\u60c5\u51b5\u8981\u76f8\u5bf9\u7b80\u5355\u4e9b\uff0c\u9664\u4e86<code>1<\/code>\u5c31\u662f<code>2<\/code>. \u5728\u5176\u4ed6\u5e73\u53f0\u4e5f\u57fa\u672c\u4e0a\u5f88\u7b80\u5355\uff0c\u56e0\u4e3a\u4e00\u822c\u5206\u8fa8\u7387\u90fd\u6bd4\u8f83\u632b\uff0c<code>devicePixelRatio<\/code>\u90fd\u662f<code>1<\/code>.<\/p>\n<p><strong>2. Android<\/strong><br \/>\n\u636e\u6211\u6240\u77e5\uff0c\u8c37\u6b4c\u7684Nexus One\u662f\u7b2c\u4e00\u4e2a\u4f7f\u7528dips\u7684\uff0c\u6bd4iphone\u8fd8\u65e9\u3002\u540c\u65f6Galaxy Nexus\u4ee5\u53caGalaxy Note\u90fd\u662f\u7c7b\u8fd0\u52a8\u89c6\u7f51\u819c\u663e\u793a\u5668\u3002\u8fd1\u8ddd\u79bb\u63a2\u7a76\u8fd9\u4e09\u4e2a\u8bbe\u5907\u5e94\u8be5\u4f1a\u6709\u6240\u6536\u83b7\u3002<\/p>\n<p>Nexus One\u5206\u8fa8\u7387\u662f480*800, \u4e3a\u4e86\u6700\u4f18\u7684\u9875\u9762\u6d4f\u89c8\uff0cAndroid WebKit\u56e2\u961f\u51b3\u5b9a\u7eb5\u5411\u624b\u6301\u65f6\u5019\u7684\u5bbd\u5ea6\u4f9d\u7136\u662f320\u50cf\u7d20\uff0c\u56e0\u6b64\uff0c<code>devicePixelRatio<\/code>\u503c\u4e3a<code>480\/320 = 1.5<\/code>.<br \/>\n\u5728\u540c\u4e00\u624b\u673a\u4e0a\uff0cOpera Mobile\u6709\u76f8\u540c\u7684\u7ed3\u8bba\uff0cdips\u4e3a320\u5bbd\uff0c<code>devicePixelRatio<\/code>\u4e5f\u662f<code>1.5<\/code> .<\/p>\n<p>\u987a\u4fbf\u63d0\u4e00\u4e0b\uff0cBlackBerry Torch 9810(OS7)\u7269\u7406\u50cf\u7d20\u540c\u6837480\u50cf\u7d20\uff0cBlackBerry WebKit\u56e2\u961f\u51b3\u5b9a\u575a\u6301<code>devicePixelRatio<\/code>\u4e3a<code>1<\/code>. \u8fd9\u53ef\u80fd\u662f\u66f4\u4e0d\u9519\u7684\u505a\u6cd5\uff0c\u5728Torch\u663e\u793a\u5668\u4e0a480px\u5bbd\u5ea6\u7ad9\u70b9\u6216\u591a\u6216\u5c11\u6709\u4e9b\u96be\u4ee5\u9605\u8bfb\u3002<\/p>\n<p>Galaxy Nexus\u6709\u50cf\u7d20\u7684\u63d0\u5347\uff0c\u4e3a720&#215;1200. Android\u56e2\u961f\u51b3\u5b9a\u63d0\u9ad8dips\u5c42\u7684\u5bbd\u5ea6\u5230360\u50cf\u7d20\u3002\u4ece\u800c\u4f7f<code>devicePixelRatio<\/code>\u4e3a<code>720\/360 = 2<\/code>. Chrome\u56e2\u961f\u51b3\u5b9a\u8ddf\u8fdb\uff0c\u5c31\u5982\u817e\u8bafQQ\u6d4f\u89c8\u5668\u6240\u505a\u7684\u90a3\u6837\u3002<\/p>\n<p>\u7136\u800c\uff0cOpera\uff0c\u575a\u6301\u81ea\u6211\uff0cdips\u5bbd\u5ea6\u4e3a320px, \u4e8e\u662f<code>devicePixelRatio<\/code>\u4e3a<code>720\/320 = 2.25<\/code>. \u4e0d\u8fc7\u4f3c\u4e4e\u8fd8\u4e0ezoom\u7f29\u653e\u5c42\u7ea7\u6709\u5173\u3002<\/p>\n<p>Galaxy Note\u7269\u7406\u50cf\u7d20\u4e3a800&#215;1200. \u8fd9\u91cc\u6240\u6709\u6d4f\u89c8\u5668\u90fd\u51b3\u5b9a\u4f7f\u7528\u4e0eGalaxy Nexus\u4e00\u6837\u7684\u6bd4\u7387\uff1aAndroid WebKit, Chrome, \u4ee5\u53caQQ\u90fd\u662f<code>2<\/code>\uff0c\u4e5f\u5c31\u610f\u5473\u7740\u5176dips\u5bbd\u5ea6\u4e3a400px. \u7136\u800c\uff0cOpera\u4f9d\u7136\u4e00\u610f\u5b64\u884c<code>2.25<\/code>, \u4e8e\u662f\u5176dips\u5bbd\u5ea6\u503c\u6709\u4e9b\u602a\u602a\u7684: 356px.<\/p>\n<p>Android\u6807\u51c6\u4f3c\u4e4e\u4e0d\u4e25\u683c\uff0c\u4e8e\u662f\u81ea\u5bb6\u4eba\u73a9\u81ea\u5bb6\u4eba\u7684\u6e38\u620f\uff0c\u5bf9\u4e8e\u5f00\u53d1\u8005\u800c\u8a00\uff0c\u53ef\u80fd\u53c8\u4f1a\u9762\u4e34\u82e6\u903c~~<\/p>\n<p><strong>3. \u89c6\u7f51\u819cMacBook<\/strong><br \/>\n\u65b0\u7684MacBook\u91c7\u7528\u89c6\u7f51\u819c\u663e\u793a\u5c4f\uff0c\u5176<code>devicePixelRatio<\/code>\u662f\uff08\u5982\u679c\u4e0d\u51fa\u610f\u5916\uff09<code>2<\/code>. \u89c6\u7f51\u819cMacBook\u7684\u7269\u7406\u50cf\u7d20\u662f2800&#215;1800\uff0c\u800c\u663e\u793a\u51fa\u5206\u8fa8\u7387\u4e3a1400&#215;900\uff0c\u5982\u679c\u628a\u5206\u8fa8\u7387\u4f5c\u4e3adips\u5c42\uff0c\u5219<code>devicePixelRatio<\/code>\u4e3a<code>2<\/code>\u5e94\u8be5\u662f\u65e0\u8bef\u7684\u3002<\/p>\n<p>\u9700\u8981\u6307\u51fa\u7684\u662f\uff0c\u5982\u679c\u4f60\u628a\u5206\u8fa8\u7387\u6539\u62101920&#215;1200\uff0c<code>devicePixelRatio<\/code>\u4f9d\u7136\u662f<code>2<\/code>. \u4e25\u683c\u6765\u8bb2\uff0c\u8fd9\u662f\u4e0d\u51c6\u786e\u7684\uff0c\u5e94\u8be5\u662f<code>1.5<\/code>, \u7136\u800c\u4f60\u4e5f\u53ef\u4ee5\u8bf4MacBook\u7684\u5206\u8fa8\u7387\u4e0d\u540c\u4e8edips\u5c42\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e0b<code>devicePixelRatio<\/code>\u5728\u53f0\u5f0f\u673a\/\u7b14\u8bb0\u672c\u4e0b\u7684\u5b9a\u4e49\u5c31\u4e0d\u4e00\u6837\uff08\u54ea\u4e00\u4e2a\uff1f\u4e0d\u77e5\u9053\u3002\uff09\u3002<\/p>\n<p>\u5728\u4efb\u4f55\u60c5\u51b5\u4e0b\uff0c\u6839\u636e\u82f9\u679c\u7684\u89c4\u8303\u505a\u6cd5\uff0c<code>devicePixelRatio<\/code>\u503c\u53ea\u53ef\u80fd\u662f<code>1<\/code>\u6216\u8005<code>2<\/code>. \u5982\u679c\u4f60\u770b\u5230<code>2<\/code>\uff0c\u4f60\u8981\u63d0\u4f9b\u89c6\u7f51\u819c\u4f18\u5316\u663e\u793a\u56fe\u7247\uff0c\u5982\u679c\u662f<code>1<\/code>\uff0c\u4f7f\u7528\u6b63\u5e38\u7684\u56fe\u7247\u2014\u2014\uff08\u8fd9\u91cc\u5185\u5bb9\u5176\u5b9e\u5c5e\u4e8e\u89c6\u7f51\u819c\u7ad9\u70b9\u7684\u5f00\u53d1\u5185\u5bb9\uff09\u3002<\/p>\n<h3>\u56db\u3001\u5176\u4ed6\u76f8\u5173\u5c5e\u6027<\/h3>\n<p>\u5f53\u9875\u9762\u8bbe\u7f6e\u4e86<code>&lt;meta name=\"viewport\" content=\"width=device-width\"&gt;<\/code>\u65f6\u5019\uff0c<code>document.documentElement.clientWidth<\/code>\u5728\u5927\u90e8\u5206\u6d4f\u89c8\u5668\u4e0b\uff0c\u5f97\u5230\u7684\u662f\u5e03\u5c40\u89c6\u533a\u7684\u5bbd\u5ea6\uff0c\u7b49\u540c\u4e8edips\u7684\u5bbd\u5ea6\u3002<\/p>\n<p>\u5bf9\u4e8e<code>screen.width<\/code>\u7684\u503c\uff1a<\/p>\n<ul id=\"ul\">\n<li>\u5728iOS\u89c6\u7f51\u819c\u8bbe\u5907\u4e0a\uff0c<code>screen.width<\/code>\u8fd4\u56dedips\u5bbd\u3002\u56e0\u6b64\uff0c\u5728\u7ad6\u7740\u663e\u793a\u7684\u65f6\u5019\uff0c\u89c6\u7f51\u819c\u663e\u793a\u5c4f\u7684ipad\u548c\u975e\u89c6\u7f51\u819c\u663e\u793a\u5c4f\u7684ipad\u8fd4\u56de\u7684\u90fd\u662f768.<\/li>\n<li>\u5728\u4e0a\u9762\u63d0\u5230\u7684\u4e09\u4e2aAndroid\u8bbe\u5907\u4e0a\uff0c<code>screen.width<\/code>\u8fd4\u56de\u7684\u662f\u7269\u7406\u50cf\u7d20\u5bbd\u5ea6\uff0c\u5206\u522b480, 720, \u548c800. \u8be5\u8bbe\u5907\u4e0a\u7684\u6240\u6709\u6d4f\u89c8\u5668\u90fd\u662f\u8be5\u503c\u3002<\/li>\n<\/ul>\n<p><a href=\"http:\/\/vasilis.nl\/\">Vasilis<\/a>\u6709\u4e00\u4e2a\u5f88\u597d\u7684\u7406\u8bba\uff1a\u82f9\u679c\u50cf\u7d20\uff0c\u56e0\u4e3a\u5b83\u60f3\u4f7f\u663e\u793a\u66f4\u6e05\u6670\uff0c\u66f4\u6d41\u7545\uff0c\u800cAndroid\u5382\u5546\u589e\u52a0\u7684\u50cf\u7d20\u5728\u5c4f\u5e55\u4e0a\u585e\u8fdb\u66f4\u591a\u7684\u4e1c\u897f\u3002\u5b83\u89e3\u91ca\u4e86\u4e3a\u4ec0\u4e48\u82f9\u679c\u5f3a\u8c03\u975e\u89c6\u7f51\u819c\u89c6\u7f51\u819c\u7684\u8fde\u7eed\u6027\uff0c\u800cAndroid\u96c6\u4e2d\u5728\u539f\u59cb\u50cf\u7d20\u6570\u3002<\/p>\n<p>Nokia Lumia Windows Phone\u4e0a\u7684IE9 <code>screen.width<\/code>\u7684\u503c\u4e0eAndroid\u8bbe\u5907\u4e00\u6837\uff0c\u8fd4\u56de\u7684\u662f\u7269\u7406\u50cf\u7d20\u3002\u800c\u4e14\u5176\u4e0d\u652f\u6301<code>devicePixelRatio<\/code>. \u56e0\u6b64\uff0c\u6211\u4eec\u65e0\u6cd5\u4ece\u4e2d\u770b\u51fa\u5176\u5bf9\u5f85\u50cf\u7d20\u7684\u6001\u5ea6\u662f\u5982\u4f55\u7684\u3002<\/p>\n<p><strong>\u5c0f\u5c0f\u7ed3\u8bba<\/strong><\/p>\n<ol>\n<li><code>devicePixelRatio<\/code>\u5728\u5927\u591a\u6570\u6d4f\u89c8\u5668\u662f\u503c\u5f97\u4fe1\u8d56\u7684\u3002<\/li>\n<li>\u5728iOS\u8bbe\u5907\uff0c<code>screen.width<\/code>\u4e58\u4ee5<code>devicePixelRatio<\/code>\u5f97\u5230\u7684\u662f\u7269\u7406\u50cf\u7d20\u503c\u3002<\/li>\n<li>\u5728Android\u4ee5\u53caWindows Phone\u8bbe\u5907\uff0c<code>screen.width<\/code>\u9664\u4ee5<code>devicePixelRatio<\/code>\u5f97\u5230\u7684\u662f\u8bbe\u5907\u72ec\u7acb\u50cf\u7d20(dips)\u503c\u3002<\/li>\n<\/ol>\n<p>\u6ce8\uff1a\u672c\u6587\u7684DIPs\u5207\u52ff\u548cDPI\u641e\u6df7\u4e86\uff01DPI\u6307\u6bcf\u82f1\u5bf8\u70b9\u7684\u4e2a\u6570\uff0c\u672c\u6587\u7684DIPs\u6307\u8bbe\u5907\u72ec\u7acb\u50cf\u7d20\u3002<\/p>\n<p>\u53c2\u8003\u6587\u7ae0\uff1a<br \/>\n<a href=\"http:\/\/www.quirksmode.org\/blog\/archives\/2012\/06\/devicepixelrati.html\">devicePixelRatio<\/a><br \/>\n<a href=\"http:\/\/www.quirksmode.org\/blog\/archives\/2012\/07\/more_about_devi.html\">More about devicePixelRatio<\/a><\/p>\n<p>\u672c\u6587\u4e3a\u539f\u521b\u6587\u7ae0\uff0c\u8f6c\u8f7d\u8bf7\u6ce8\u660e\u6765\u81ea<a href=\"http:\/\/www.zhangxinxu.com\/\">\u5f20\u946b\u65ed-\u946b\u7a7a\u95f4-\u946b\u751f\u6d3b<\/a>[<a href=\"http:\/\/www.zhangxinxu.com\/\">http:\/\/www.zhangxinxu.com<\/a>]<br \/>\n\u672c\u6587\u5730\u5740\uff1a<a href=\"http:\/\/www.zhangxinxu.com\/wordpress\/?p=2568\">http:\/\/www.zhangxinxu.com\/wordpress\/?p=2568<\/a><\/p>\n<p>\uff08\u672c\u7bc7\u5b8c\uff09<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u672c\u6587\u6240\u8bf4devicePixelRatio\u5176\u5b9e\u6307\u7684\u662fwindow.devicePixelRatio, \u88ab\u6240\u6709WebKit\u6d4f\u89c8\u5668\u4ee5\u53caOpera\u6240\u652f\u6301\uff0c\u968f\u7740\u663e\u793a\u5668\u7684\u53d1\u5c55\uff0c\u8fd9\u4e2a\u5c5e\u6027\u4e5f\u6162\u6162\u767b\u4e0a\u4e86\u524d\u7aef\u6280\u672f\u7684\u821e\u53f0\u3002<br \/>\n\u672c\u6587\u5185\u5bb9\u5927\u90e8\u5206\u5c5e\u4e8e\u7ffb\u8bd1\u6027\u8d28\u5185\u5bb9\uff0c\u56e0\u6b64\uff0c\u4f1a\u4e0d\u90a3\u4e48\u901a\u4fd7\u6613\u61c2\u3002\u4e0d\u8fc7\uff0c\u4f60\u662f\u505a\u624b\u673a\u5f00\u53d1\u7684\uff0c\u6216\u662f\u6709\u610f\u5411\u7684\uff0c\u672c\u6587\u7684\u5185\u5bb9\u5982\u679c\u7ec6\u7ec6\u8bfb\u6765\uff0c\u8fd8\u662f\u6709\u4e9b\u6536\u83b7\u7684\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[648],"tags":[743,158,230,744],"_links":{"self":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/2568"}],"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=2568"}],"version-history":[{"count":0,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/2568\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/media?parent=2568"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/categories?post=2568"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/tags?post=2568"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}