{"id":70,"date":"2017-12-30T19:07:32","date_gmt":"2017-12-30T11:07:32","guid":{"rendered":"https:\/\/www.aberlt.com\/?p=70"},"modified":"2024-04-18T19:43:34","modified_gmt":"2024-04-18T11:43:34","slug":"uitableview-%e6%b5%81%e7%95%85%e5%ba%a6%e4%bc%98%e5%8c%96%e5%ae%9e%e8%b7%b5","status":"publish","type":"post","link":"https:\/\/www.aberlt.com\/index.php\/2017\/12\/30\/uitableview-%e6%b5%81%e7%95%85%e5%ba%a6%e4%bc%98%e5%8c%96%e5%ae%9e%e8%b7%b5\/","title":{"rendered":"UITableView \u6d41\u7545\u5ea6\u4f18\u5316\u5b9e\u8df5"},"content":{"rendered":"<p>11 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decoding=\"async\" src=\"http:\/\/images.aberlt.com\/2018-03-13-Before_fluency_optimization.gif\" alt=\"Before_fluency_optimization\" \/><\/p>\n<p>\u4f18\u5316\u540e\uff1a<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.aberlt.com\/2018-03-12-After_fluency_optimization.gif\" alt=\"After_fluency_optimization\" \/><\/p>\n<h2>\u5c4f\u5e55\u663e\u793a\u7684\u539f\u7406<\/h2>\n<p><img decoding=\"async\" src=\"http:\/\/images.aberlt.com\/2018-01-01-ios_screen_display.png\" alt=\"ios_screen_display\" \/><\/p>\n<p>\u7ecf\u8fc7\u67e5\u9605\u8d44\u6599\uff0c\u56fe\u50cf\u663e\u793a\u5230\u5c4f\u5e55\u9700\u8981\u7ecf\u8fc7\u5982\u4e0a\u56fe\u6240\u793a\u7684\u8fc7\u7a0b\u8fdb\u884c\u5904\u7406\u3002<\/p>\n<p>\u9996\u5148\uff0cCPU \u628a\u89c6\u56fe\u521b\u5efa\u3001\u5e03\u5c40\u8ba1\u7b97\u3001\u56fe\u7247\u89e3\u7801\u3001\u6587\u672c\u7ed8\u5236\u7b49\u663e\u793a\u5185\u5bb9\u8ba1\u7b97\u597d\u63d0\u4ea4\u7ed9 GPU\uff1b\u7136\u540e GPU \u5bf9\u5185\u5bb9\u8fdb\u884c\u53d8\u6362\u3001\u5408\u6210\u3001\u6e32\u67d3\u5e76\u5c06\u6e32\u67d3\u7ed3\u679c\u653e\u5165\u5e27\u7f13\u51b2\u533a FrameBuffer\uff1b\u6700\u540e\u89c6\u9891\u63a7\u5236\u5668\u901a\u8fc7<strong>\u5782\u76f4\u540c\u6b65\u4fe1\u53f7\uff08V-Sync\uff09<\/strong>\u9010\u884c\u8bfb\u53d6\u5e27\u7f13\u51b2\u533a\u7684\u6570\u636e\u5e76\u8f6c\u6362\u540e\u4f20\u9012\u7ed9\u5c4f\u5e55\u663e\u793a\u3002<\/p>\n<h3>\u53cc\u7f13\u51b2\u673a\u5236\u548c\u5782\u76f4\u540c\u6b65\u673a\u5236<\/h3>\n<p>iOS \u8bbe\u5907\u4e3a\u4e86\u63d0\u5347\u6548\u7387\u4f7f\u7528\u4e86\u53cc\u7f13\u51b2\u673a\u5236\u3002\u5176\u539f\u7406\u662f GPU \u5148\u5c06\u4e00\u4e2a\u6e32\u67d3\u7ed3\u679c\u653e\u5165\u4e00\u4e2a\u7f13\u51b2\u533a\u8ba9\u89c6\u9891\u63a7\u5236\u5668\u8bfb\u53d6\uff0c\u5f53\u4e0b\u4e00\u4e2a\u5185\u5bb9\u6e32\u67d3\u5b8c\u6210\u540e\uff0cGPU \u4f1a\u5c06\u89c6\u9891\u63a7\u5236\u5668\u7684\u6307\u9488\u76f4\u63a5\u6307\u5411\u7b2c\u4e8c\u4e2a\u7f13\u51b2\u533a\u3002<\/p>\n<p>\u4f46\u53cc\u7f13\u51b2\u673a\u5236\u4f1a\u56e0\u4e3a\u89c6\u9891\u63a7\u5236\u5668\u8bfb\u53d6\u901f\u5ea6\u4e0e GPU \u6e32\u67d3\u901f\u5ea6\u7684\u4e0d\u540c\u6b65\u9020\u6210\u56fe\u50cf\u6495\u88c2\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0cGPU \u91c7\u7528\u4e86\u5782\u76f4\u540c\u6b65\u673a\u5236\uff0c\u5373\u7b49\u5f85\u663e\u793a\u5668\u7684 VSync \u4fe1\u53f7\u53d1\u51fa\u540e\u624d\u8fdb\u884c\u65b0\u7684\u6e32\u67d3\u548c\u7f13\u51b2\u533a\u7684\u66f4\u65b0\u3002<\/p>\n<p>\u53cc\u7f13\u51b2\u548c\u5782\u76f4\u540c\u6b65\u4e24\u79cd\u673a\u5236\u7684\u4f7f\u7528\u63d0\u5347\u4e86\u5c4f\u5e55\u5237\u65b0\u7684\u6548\u7387\u548c\u753b\u9762\u7684\u6d41\u7545\u5ea6\uff0c\u4f46\u4e5f\u589e\u52a0\u4e86\u8d44\u6e90\u7684\u6d88\u8017\u3002<\/p>\n<h2>\u5361\u987f\u7684\u4ea7\u751f<\/h2>\n<p>\u5df2\u77e5\u5782\u76f4\u540c\u6b65\u673a\u5236\u4e2d\u4e00\u4e2a VSync \u4fe1\u53f7\u4ea7\u751f\u5c06\u4f1a\u5f15\u8d77\u4e00\u4e2a\u65b0\u7684\u5185\u5bb9\u8ba1\u7b97\u548c\u6e32\u67d3\u7684\u6d41\u7a0b\uff0c\u5728\u4e0b\u4e00\u4e2a VSync \u4fe1\u53f7\u4ea7\u751f\u4e4b\u524d\uff0c\u5c31\u9700\u8981\u5b8c\u6210\u4ece CPU \u7684\u8ba1\u7b97\u5230\u5c4f\u5e55\u7684\u663e\u793a\u8fd9\u4e2a\u6d41\u7a0b\u3002\u4f46\u662f\u5e76\u4e0d\u80fd\u4fdd\u8bc1\u6bcf\u4e00 CPU \u6216\u8005 GPU \u90fd\u80fd\u591f\u5728\u4e24\u4e2a VSync \u4e4b\u95f4\u7684\u65f6\u95f4\u5185\u5b8c\u6210\u4efb\u52a1\uff0c\u800c\u8fd9\u4e2a\u6ca1\u6709\u53ca\u65f6\u5b8c\u6210\u7684\u4efb\u52a1\u5c06\u4f1a\u88ab\u820d\u5f03\uff0c\u6b64\u65f6\u5c4f\u5e55\u7684\u5185\u5bb9\u5c31\u6ca1\u6709\u88ab\u66f4\u65b0\uff0c\u6240\u4ee5\u9020\u6210\u4e86\u5361\u987f\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.aberlt.com\/2018-01-01-ios_frame_drop.png\" alt=\"ios_frame_drop\" \/><\/p>\n<p>\u56e0\u6b64\uff0c\u6211\u4eec\u9700\u8981\u4ece CPU \u548c GPU \u5728\u8fd9\u4e2a\u8fc7\u7a0b\u4e2d\u6240\u6267\u884c\u7684\u4efb\u52a1\u5165\u624b\uff0c\u627e\u5230\u53ef\u4ee5\u8fdb\u884c\u4f18\u5316\u7684\u5730\u65b9\u3002<\/p>\n<h2>\u4f18\u5316<\/h2>\n<h3>CPU \u5728\u5c4f\u5e55\u663e\u793a\u8fc7\u7a0b\u4e2d\u6267\u884c\u7684\u4efb\u52a1\u53ca\u672c\u4eba\u8fdb\u884c\u4f18\u5316\u7684\u5185\u5bb9<\/h3>\n<p>CPU \u6267\u884c\u7684\u4efb\u52a1\u4e3b\u8981\u662f\uff1a<\/p>\n<ul>\n<li>\u521b\u5efa\u5bf9\u8c61<\/li>\n<li>\u8c03\u6574\u5bf9\u8c61<\/li>\n<li>\u9500\u6bc1\u5bf9\u8c61<\/li>\n<li>\u5e03\u5c40\u8ba1\u7b97<\/li>\n<li>\u6587\u672c\u8ba1\u7b97<\/li>\n<li>\u6587\u672c\u7ed8\u5236<\/li>\n<li>\u56fe\u7247\u89e3\u7801<\/li>\n<\/ul>\n<p>\u8fd9\u91cc\u6bcf\u4e2a\u4efb\u52a1\u90fd\u6709\u53ef\u4f18\u5316\u7684\u5730\u65b9\uff0c\u800c\u6211\u5728\u4f18\u5316\u7684\u8fc7\u7a0b\u4e2d\u5219\u6839\u636e\u9879\u76ee\u7684\u5b9e\u9645\u60c5\u51b5\u5bf9\u51e0\u4e2a\u4efb\u52a1\u8fdb\u884c\u4e86\u4f18\u5316\u3002<\/p>\n<h4>\u521b\u5efa\u5bf9\u8c61<\/h4>\n<p>\u7531\u4e8e\u5217\u8868\u4e2d\u53ea\u6709\u4e00\u4e2a <code>UITableViewCell<\/code> \u4e2d\u7684\u4e00\u4e2a\u5b50\u63a7\u4ef6\u9700\u8981\u54cd\u5e94\u89e6\u6478\u4e8b\u4ef6\uff0c\u6240\u4ee5\u6211\u5c06\u539f\u6765\u4f7f\u7528\u7684 <code>UIView<\/code>\u3001<code>UIImageView<\/code> \u7b49\u63a7\u4ef6\u6539\u4e3a\u4f7f\u7528 <code>CALayer<\/code>\u3002\u8fd9\u91cc\u4e3b\u8981\u662f\u56e0\u4e3a <code>CALyer<\/code> \u76f8\u5bf9\u6765\u8bf4\u66f4\u52a0\u8f7b\u91cf\uff0c\u800c\u4e14\u539f\u6765\u7684\u63a7\u4ef6\u6709\u5f88\u591a\u5c5e\u6027\u7684\u8bbe\u7f6e\u5176\u5b9e\u8fd8\u662f\u5728\u5bf9 <code>CALayer<\/code> \u8fdb\u884c\u64cd\u4f5c\u3002<\/p>\n<h4>\u5e03\u5c40\u8ba1\u7b97<\/h4>\n<p>\u539f\u6765\u9879\u76ee\u4e2d\u4f7f\u7528 <code>Masonary<\/code> \u5bf9\u63a7\u4ef6\u8fdb\u884c\u5e03\u5c40\uff0c\u8fd9\u5728\u5f00\u53d1\u7684\u65f6\u5019\u975e\u5e38\u65b9\u4fbf\uff0c\u4f46\u662f\u7a0b\u5e8f\u5728\u8fd0\u884c\u7684\u65f6\u5019\u8ba1\u7b97\u91cf\u5f88\u5927\uff0c\u540c\u65f6\u8fd8\u9700\u8981\u5bf9\u63a7\u4ef6\u7684 <code>frame\/bounds\/center<\/code> \u7b49\u5c5e\u6027\u8fdb\u884c\u8c03\u6574\uff0c\u9700\u8981\u6d88\u8017\u5f88\u591a\u7684\u8d44\u6e90\u8fdb\u800c\u9020\u6210\u6027\u80fd\u7684\u635f\u5931\u3002<\/p>\n<p>\u56e0\u6b64\uff0c\u6211\u5c06\u81ea\u52a8\u5e03\u5c40\u6539\u4e3a\u901a\u8fc7 frame \u5e03\u5c40\uff0c\u5728\u83b7\u53d6\u5230\u6570\u636e\u7684\u65f6\u5019\u63d0\u524d\u5bf9\u5e03\u5c40\u8fdb\u884c\u8ba1\u7b97\u5e76\u5b58\u50a8\u5230\u5e03\u5c40\u6a21\u578b\u4e2d\uff0cTableView \u53ef\u4ee5\u76f4\u63a5\u4ece\u5e03\u5c40\u6a21\u578b\u83b7\u53d6 Cell \u7684\u9ad8\u5ea6\uff0cCell \u4e5f\u53ef\u4ee5\u76f4\u63a5\u83b7\u53d6\u5404\u4e2a\u5b50\u63a7\u4ef6\u7684\u4f4d\u7f6e\u548c\u5c3a\u5bf8\u7b49\u4fe1\u606f\uff0c\u907f\u514d\u591a\u6b21\u8ba1\u7b97\uff0c\u8282\u7701\u8d44\u6e90\u7684\u6d88\u8017\u548c\u5185\u5b58\u7684\u5360\u7528\u3002<\/p>\n<h4>\u6587\u672c\u8ba1\u7b97\u548c\u6e32\u67d3<\/h4>\n<p>\u539f\u9879\u76ee\u4e2d\u4f7f\u7528 <code>UILabel<\/code> \u663e\u793a\u6587\u672c\uff0c\u7531\u4e8e\u5bf9\u884c\u9ad8\u6709\u7279\u522b\u7684\u8981\u6c42\uff0c\u9700\u8981\u5c06\u5185\u5bb9\u5904\u7406\u4e3a\u5bcc\u6587\u672c\u3002\u8fd9\u4e9b\u90fd\u662f\u5728 Cell \u521d\u59cb\u5316\u7684\u65f6\u5019\u8fdb\u884c\u64cd\u4f5c\u7684\uff0c\u5e76\u4e14\u662f\u5728\u4e3b\u7ebf\u7a0b\u64cd\u4f5c\uff0c\u8fd9\u5bf9\u4e3b\u7ebf\u7a0b\u9020\u6210\u4e86\u4e00\u5b9a\u7684\u963b\u585e\u3002<\/p>\n<p>\u7531\u4e8e\u9879\u76ee\u4e2d\u521a\u597d\u5f15\u7528\u4e86 <code>YYKit<\/code>\uff0c\u6211\u51b3\u5b9a\u4f7f\u7528\u6587\u672c\u5e03\u5c40\u7c7b <code>YYTextLayout<\/code> \u8fdb\u884c\u6587\u672c\u7684\u8ba1\u7b97\u548c\u5bcc\u6587\u672c\u7684\u7ed8\u5236\u5e76\u5c06\u5176\u4fdd\u5b58\u5728\u5e03\u5c40\u6a21\u578b\u4e2d\u4ee5\u4f9b\u540e\u9762\u6e32\u67d3\u4f7f\u7528\uff1b\u4f7f\u7528 <code>YYLabel<\/code> \u6765\u505a\u6587\u672c\u7684\u5f02\u6b65\u6e32\u67d3\uff0c\u5c06\u6e32\u67d3\u7684\u5de5\u4f5c\u653e\u5230\u5b50\u7ebf\u7a0b\u8fdb\u884c\u3002\u65e2\u907f\u514d\u4e86\u963b\u585e\u4e3b\u7ebf\u7a0b\uff0c\u8fd8\u51cf\u5c11\u4e86\u4f7f\u7528 <code>UILabel<\/code> \u65f6\u7684\u5f88\u591a\u8ba1\u7b97\u3002<\/p>\n<blockquote>\n<p>\u56e0\u4e3a\u539f\u6765\u9879\u76ee\u4e2d\u8c03\u6574\u5bf9\u8c61\u7684\u64cd\u4f5c\u6bd4\u8f83\u5c11\uff0c\u800c\u56fe\u7247\u5219\u4f7f\u7528\u4e86 <code>YYWebImage<\/code> \u8fdb\u884c\u5f02\u6b65\u52a0\u8f7d\uff0c\u6240\u4ee5\u8fd9\u4e24\u5904\u6ca1\u6709\u8fdb\u884c\u5904\u7406\u3002<br \/>\n\u81f3\u4e8e\u5bf9\u8c61\u7684\u9500\u6bc1\uff0c\u76ee\u524d\u5e76\u6ca1\u6709\u9020\u6210\u591a\u5927\u7684\u5f71\u54cd\u3002\u4e3a\u4e86\u907f\u514d\u7531\u4e8e\u64cd\u4f5c\u4e0d\u5f53\u9020\u6210\u95ee\u9898\uff0c\u6240\u4ee5\u6ca1\u6709\u4ece\u8fd9\u4e2a\u65b9\u9762\u5165\u624b\u3002<\/p>\n<\/blockquote>\n<h3>GPU \u5728\u5c4f\u5e55\u663e\u793a\u8fc7\u7a0b\u4e2d\u6267\u884c\u7684\u4efb\u52a1\u53ca\u53ef\u4f18\u5316\u7684\u5185\u5bb9<\/h3>\n<p>GPU \u6267\u884c\u7684\u4efb\u52a1\u662f\uff1a<\/p>\n<ul>\n<li>\u6e32\u67d3\u7eb9\u7406<\/li>\n<li>\u6df7\u5408\u89c6\u56fe<\/li>\n<li>\u751f\u6210\u56fe\u5f62<\/li>\n<\/ul>\n<p>\u76f8\u5bf9\u6765\u8bf4 GPU \u6267\u884c\u7684\u4efb\u52a1\u7c7b\u578b\u6ca1\u6709 CPU \u90a3\u4e48\u591a\u3002\u5728\u8fd9\u4e2a\u73af\u8282\u6211\u4ece<strong>\u6df7\u5408\u89c6\u56fe<\/strong>\u548c<strong>\u751f\u6210\u56fe\u5f62<\/strong>\u4e24\u4e2a\u65b9\u9762\u5165\u624b\u8fdb\u884c\u4f18\u5316\u3002<\/p>\n<h4>\u6df7\u5408\u89c6\u56fe<\/h4>\n<p>\u5f00\u53d1\u8fc7\u7a0b\u4e2d\u4e3a\u4e86\u5b9e\u73b0\u67d0\u4e9b\u9700\u6c42\u5e38\u5e38\u4f1a\u4f7f\u5f97\u4e00\u4e2a\u89c6\u56fe\u4e0a\u6709\u5f88\u591a\u4e2a\u63a7\u4ef6\u5c42\u53e0\u5728\u4e00\u8d77\uff0c\u5bfc\u81f4\u89c6\u56fe\u5c42\u7ea7\u592a\u591a\u3001\u7ed3\u6784\u590d\u6742\u3002\u7279\u522b\u662f\u5bf9\u4e8e\u900f\u660e\u7684\u63a7\u4ef6\uff0cGPU \u9700\u8981\u8ba1\u7b97\u591a\u4e2a\u89c6\u56fe\u6df7\u5408\u540e\u7684\u6548\u679c\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u4f1a\u6d88\u8017\u66f4\u591a\u7684\u8d44\u6e90\u3002<\/p>\n<p>\u8fd9\u91cc\u6211\u505a\u7684\u5c31\u662f\u5c06\u80fd\u591f\u7ec4\u5408\u5728\u4e00\u8d77\u7684\u89c6\u56fe\u7ed8\u5236\u6210\u5bcc\u6587\u672c\u6216\u8005\u4e0e\u5176\u5b83\u89c6\u56fe\u4e00\u8d77\u5408\u6210\u4e00\u5f20\u56fe\u7247\uff0c\u51cf\u5c11\u89c6\u56fe\u7684\u5c42\u7ea7\u3002\u540c\u65f6\u5c06\u4e0d\u9700\u8981\u900f\u660e\u7684\u89c6\u56fe\u90fd\u8bbe\u7f6e\u4e86\u4e0e\u7236\u89c6\u56fe\u4e00\u6837\u7684\u989c\u8272\uff0c\u5c06 opaque \u8bbe\u7f6e\u4e3a YES\u3002<\/p>\n<h4>\u751f\u6210\u56fe\u5f62<\/h4>\n<p>\u539f\u9879\u76ee\u7684\u5217\u8868\u4e2d\u51e0\u4e4e\u6bcf\u4e2a Cell \u90fd\u6709\u4e00\u4e2a\u5706\u5f62\u7684\u56fe\u6807\uff0c\u5b9e\u73b0\u8fd9\u4e2a\u9700\u6c42\u7684\u505a\u6cd5\u662f\u901a\u8fc7\u8bbe\u7f6e <code>CALayer<\/code> \u7684 <code>cornerRadius<\/code> \u548c <code>masksToBounds<\/code> \u5b8c\u6210\u7684\u3002\u4f17\u6240\u5468\u77e5\uff0c\u8fd9\u4e24\u4e2a\u5c5e\u6027\u5206\u5f00\u4f7f\u7528\u7684\u65f6\u5019\u6ca1\u95ee\u9898\uff0c\u4f46\u662f\u4e00\u8d77\u4f7f\u7528\u7684\u8bdd\u5c31\u5fc5\u5b9a\u4f1a\u9020\u6210\u79bb\u5c4f\u6e32\u67d3\uff08Off-Screen rendering\uff09\u3002<\/p>\n<p>\u79bb\u5c4f\u6e32\u67d3\u9700\u8981\u5148\u5728\u5c4f\u5e55\u5916\uff08Off-Screen\uff09\u6e32\u67d3\u5b8c\u6210\u540e\u518d\u7ed8\u5236\u5230\u5f53\u524d\u5c4f\u5e55\uff08On-Screen\uff09\uff0c\u8fd9\u91cc\u9700\u8981\u53e6\u5916\u5206\u914d\u4e00\u5757\u5185\u5b58\u8fdb\u884c\u6e32\u67d3\uff0c\u800c\u4e14 On-Screen \u548c Off-Screen \u4e4b\u95f4\u7684\u4e0a\u4e0b\u6587\u73af\u5883\u5207\u6362\u7684\u8fc7\u7a0b\u9700\u8981\u5f88\u5927\u7684\u5f00\u9500\u3002<\/p>\n<p>\u7f51\u4e0a\u6709\u5f88\u591a\u89e3\u51b3\u79bb\u5c4f\u6e32\u67d3\u7684\u65b9\u6cd5\uff0c\u6211\u91c7\u7528\u4e86\u6bd4\u8f83\u5f7b\u5e95\u7684\u89e3\u51b3\u65b9\u6cd5\uff0c\u76f4\u63a5\u5728\u540e\u53f0\u901a\u8fc7\u91cd\u7ed8\u5c06\u56fe\u7247\u88c1\u526a\u4e3a\u5706\u89d2\u3002<\/p>\n<h3>\u4f18\u5316\u540e\u5217\u8868\u7684\u52a0\u8f7d\u8fc7\u7a0b<\/h3>\n<p><img decoding=\"async\" src=\"http:\/\/images.aberlt.com\/2018-01-03-List_show_flow.png\" alt=\"List_show_flow\" \/><\/p>\n<p>\u4f18\u5316\u601d\u8def\u5f88\u7b80\u5355\uff0c\u4f46\u662f\u5b9e\u9645\u64cd\u4f5c\u8d77\u6765\u5de5\u4f5c\u91cf\u6bd4\u8f83\u5927\uff0c\u4e5f\u6709\u4e0d\u5c11\u5751\uff0c\u8fd9\u91cc\u8bf4\u4e00\u4e0b\u6700\u5927\u7684\u5751 <code>CALayer<\/code> \u7684\u5149\u6805\u5316\u5c5e\u6027 <code>shouldRasterize<\/code>\u3002<\/p>\n<h4>shouldRasterize<\/h4>\n<p>\u5728\u8c03\u7814\u7684\u65f6\u5019\u770b\u5230\u7f51\u4e0a\u7684\u8d44\u6599\u8bf4\u8bbe\u7f6e\u8fd9\u4e2a\u5c5e\u6027\u53ef\u4ee5\u63d0\u9ad8\u6027\u80fd\uff0c\u4fbf\u5728\u4f18\u5316\u7684\u65f6\u5019\u5c1d\u8bd5\u4e86\u4e00\u4e0b\uff0c\u5c06\u5706\u89d2\u56fe\u6807\u7684\u5706\u6846\u8bbe\u7f6e\u4e86\u8fd9\u4e2a\u5c5e\u6027\uff0c\u4f46\u662f\u7ed3\u679c\u5374\u4e0d\u5c3d\u4eba\u610f\u3002\u5f53\u9875\u9762\u51fa\u73b0\u6bd4\u8f83\u591a\u7684\u5706\u89d2\u56fe\u6807\u65f6\uff0c\u52a0\u8f7d\u51e0\u9875\u7684\u5185\u5bb9\u4e4b\u540e\u5c31\u4f1a\u53d8\u5f97\u5f02\u5e38\u5361\u987f\uff0c\u8089\u773c\u80fd\u591f\u975e\u5e38\u660e\u663e\u7684\u611f\u53d7\u5230\uff0cFPS \u4e5f\u6781\u901f\u4e0b\u964d\uff0c\u4f46\u662f\u901a\u8fc7 Time Profile \u548c Core Animation \u5de5\u5177\u65e0\u6cd5\u6392\u67e5\u51fa\u95ee\u9898\uff0c\u540e\u6765\u901a\u8fc7\u5bf9\u63a7\u4ef6\u7684\u5220\u51cf\u6392\u67e5\u624d\u77e5\u9053\u662f\u8fd9\u4e2a\u5c5e\u6027\u5bfc\u81f4\u7684\u95ee\u9898\u3002<\/p>\n<p>\u5f00\u542f <code>shouldRasterize<\/code> \u540e <code>CAlayer<\/code> \u4f1a\u88ab\u5149\u6805\u5316\u4e3a\u4f4d\u56fe bitmap \u4fdd\u5b58\u5728\u7f13\u5b58\u4e2d\u4ee5\u5907\u91cd\u7528\uff0c\u53ef\u4ee5\u52a0\u5feb\u6e32\u67d3\u8fc7\u7a0b\u3002\u4f46\u662f\u4f7f\u7528\u7684\u8fc7\u7a0b\u9700\u8981\u6ce8\u610f\u51e0\u4e2a\u95ee\u9898\uff1a<\/p>\n<ul>\n<li>\u4e0d\u8981\u5bf9\u7ecf\u5e38\u53d8\u52a8\u7684\u5185\u5bb9\u5f00\u542f\uff0c\u56e0\u4e3a\u4e00\u65e6\u66f4\u65b0\u5df2\u7ecf\u5149\u6805\u5316\u7684 layer \u4f1a\u9020\u6210\u5927\u91cf\u79bb\u5c4f\u6e32\u67d3<\/li>\n<li>\u4e0d\u8981\u8fc7\u5ea6\u4f7f\u7528\uff0c\u7cfb\u7edf\u9650\u5236\u7f13\u5b58\u7684\u5927\u5c0f\u4e3a 2.5x screen size\uff0c\u8fc7\u5ea6\u4f7f\u7528\u7684\u8bdd\u4e5f\u4f1a\u9020\u6210\u79bb\u5c4f\u6e32\u67d3<\/li>\n<li>\u5149\u6805\u5316\u7684\u4f4d\u56fe\u5982\u679c\u8d85\u8fc7 100 \u6beb\u79d2\u6ca1\u6709\u88ab\u4f7f\u7528\u5219\u4f1a\u88ab\u79fb\u9664\uff0c\u6240\u4ee5\u5bf9\u4e8e\u4e0d\u8fde\u7eed\u4f7f\u7528\u7684\u5185\u5bb9\u8fdb\u884c\u5149\u6805\u5316\u662f\u65e2\u6ca1\u6709\u610f\u4e49\u53c8\u6d6a\u8d39\u8d44\u6e90\u7684<\/li>\n<\/ul>\n<p>\u5982\u56fe\u4e3a WWDC 2014 \u7684\u5185\u5bb9\uff1a<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/images.aberlt.com\/2018-01-03-Rasterization.png\" alt=\"Rasterization\" \/><\/p>\n<p>\u800c\u6211\u5728\u4f18\u5316\u8fc7\u7a0b\u4e2d\u72af\u7684\u9519\u8bef\u5c31\u662f\u7b2c\u4e00\u4e2a\u9700\u8981\u6ce8\u610f\u7684\u95ee\u9898\uff1a<\/p>\n<p>\u628a\u6dfb\u52a0\u5230 TableViewCell \u7684 layer \u8fdb\u884c\u4e86\u5149\u6805\u5316\uff0c\u800c TableViewCell \u7531\u4e8e\u590d\u7528\u7684\u539f\u56e0\u9700\u8981\u9891\u7e41\u7684\u8fdb\u884c\u91cd\u7ed8\uff0c\u5bf9\u5df2\u7ecf\u5149\u6805\u5316\u7684\u5185\u5bb9\u8fdb\u884c\u4e86\u66f4\u65b0\uff0c\u5bfc\u81f4\u5927\u91cf\u7684\u79bb\u5c4f\u6e32\u67d3\uff0c\u6240\u4ee5\u5217\u8868\u7684\u6d41\u7545\u5ea6\u624d\u4f1a\u6781\u901f\u4e0b\u964d\u3002<\/p>\n<h2>\u603b\u7ed3<\/h2>\n<p>\u8fd9\u6b21\u4f18\u5316\u4e2d\u67e5\u8be2\u4e86\u5f88\u591a\u8d44\u6599\uff0c\u4e86\u89e3\u5230\u4e0d\u5c11\u7684\u539f\u7406\u77e5\u8bc6\uff0c\u5bf9\u4e8e\u89c6\u56fe\u662f\u5982\u4f55\u7ed8\u5236\u5230\u5c4f\u5e55\u4e0a\u4e5f\u66f4\u52a0\u4e86\u89e3\uff0c\u4e5f\u66f4\u80fd\u9488\u5bf9\u6027\u5730\u8fdb\u884c\u5206\u6790\u548c\u4f18\u5316\uff0c\u5728\u8fd9\u4e2a\u8fc7\u7a0b\u4e2d\u4e5f\u5b66\u4f1a\u4e86\u5982\u4f55\u4f7f\u7528 Time Profile \u548c Core Animation \u5de5\u5177\u8fdb\u884c\u68c0\u6d4b\u3002<\/p>\n<p>\u4ece\u8fd9\u6b21\u7684\u8e29\u5751\u9886\u609f\u5230\u4e86\u4e0d\u5e94\u8be5\u4eba\u4e91\u4ea6\u4e91\uff0c\u5bf9\u4e8e\u522b\u4eba\u63d0\u51fa\u7684\u4e1c\u897f\u8981\u81ea\u5df1\u53bb\u9a8c\u8bc1\u662f\u5426\u6b63\u786e\u3001\u662f\u5426\u9002\u5408\u8fd0\u7528\u5230\u81ea\u5df1\u7684\u9879\u76ee\u4e2d\u3002\u4e00\u65e6\u51fa\u73b0\u65e0\u6cd5\u76f4\u63a5\u5224\u65ad\u3001\u5de5\u5177\u4e5f\u65e0\u6cd5\u6392\u67e5\u51fa\u7684\u95ee\u9898\u5e94\u8be5\u8981\u9010\u6b65\u53bb\u5bf9\u4ee3\u7801\u8fdb\u884c\u6821\u9a8c\u5b9a\u4f4d\u95ee\u9898\u6240\u5728\u3002<\/p>\n<h2>\u53c2\u8003<\/h2>\n<p><a href=\"https:\/\/blog.ibireme.com\/2015\/11\/12\/smooth_user_interfaces_for_ios\/\">iOS \u4fdd\u6301\u754c\u9762\u6d41\u7545\u7684\u6280\u5de7<\/a><\/p>\n<p><a href=\"https:\/\/icetime17.github.io\/2015\/07\/04\/2015-07\/iOS-UITableView\u7684\u4f18\u5316\u6280\u5de7\/\">iOS \u2014 UITableView\u7684\u4f18\u5316\u6280\u5de7<\/a><\/p>\n<p><a href=\"https:\/\/github.com\/100mango\/zen\/blob\/master\/WWDC\u5fc3\u5f97\uff1aAdvanced%20Graphics%20and%20Animations%20for%20iOS%20Apps\/Advanced%20Graphics%20and%20Animations%20for%20iOS%20Apps.md\">WWDC\u5fc3\u5f97\uff1aAdvanced Graphics and Animations for iOS Apps<\/a><\/p>\n<p><a href=\"http:\/\/iandai.github.io\/blog\/2015\/09\/21\/gao-xing-neng-tian-jia-tu-pian-yuan-jiao-fang-fa-bi-jiao-:layer-dot-shouldrasterize,layer-dot-setshadowpathhe-tou-ming-tu-pian\/\">\u9ad8\u6027\u80fd\u6dfb\u52a0\u56fe\u7247\u5706\u89d2\u65b9\u6cd5\u539f\u7406\uff1acornerRadius\uff0clayer.shouldRasterize\uff0clayer.setShadowPath\u548c\u900f\u660e\u56fe\u7247<\/a><\/p>\n<p><a href=\"http:\/\/www.jianshu.com\/p\/080108c969e8\">iOS\u6027\u80fd\u4f18\u5316\uff08\u4e00\uff09\uff1aTime Profile<\/a><\/p>\n<p><a href=\"https:\/\/www.jianshu.com\/p\/2a01e5e2141f\">iOS app\u6027\u80fd\u4f18\u5316\u7684\u90a3\u4e9b\u4e8b(\u4e8c)<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>11 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