“`” \u8003\u67e5\u70b9<\/p>\n
\u6211\u8bb0\u5f97\u5728\u521a\u63a5\u89e6iOS\u7684\u65f6\u5019\u5bf9\u8fd9\u4e2aARC\u548cMRC\u5c31\u8ba8\u8bba\u9887\u6df1\uff0c\u8ba4\u4e3aARC\u662f\u5bf9\u7a0b\u5e8f\u5458\u7684\u4e00\u79cd\u798f\u5229\uff0c\u8ba9\u6211\u4eec\u8282\u7701\u4e86\u5927\u91cf\u7684\u4ee3\u7801\uff0c\u90a3\u4e48ARC\u662f\u4ec0\u4e48\u5462\uff1f<\/p>\n
ARC \u662f\u82f9\u679c\u5728 WWDC 2011 \u63d0\u51fa\u6765\u7684\u6280\u672f\uff0c\u56e0\u6b64\u5f88\u591a\u65b0\u5165\u884c\u7684\u540c\u5b66\u53ef\u80fd\u5bf9\u6b64\u6280\u672f\u7ec6\u8282\u5e76\u4e0d\u719f\u6089\u3002\u4f46\u662f\uff0c\u867d\u7136 ARC \u6781\u5927\u5730\u7b80\u5316\u4e86\u6211\u4eec\u7684\u5185\u5b58\u7ba1\u7406\u5de5\u4f5c\uff0c\u4f46\u662f\u5f15\u7528\u8ba1\u6570\u8fd9\u79cd\u5185\u5b58\u7ba1\u7406\u65b9\u6848\u5982\u679c\u4e0d\u88ab\u7406\u89e3\uff0c\u90a3\u4e48\u5c31\u65e0\u6cd5\u5904\u7406\u597d\u90a3\u4e9b\u68d8\u624b\u7684\u5faa\u73af\u5f15\u7528\u95ee\u9898\u3002\u6240\u4ee5\uff0c\u8fd9\u9053\u9762\u8bd5\u9898\u5176\u5b9e\u662f\u8003\u67e5\u540c\u5b66\u5bf9\u4e8e iOS \u7a0b\u5e8f\u5185\u5b58\u7ba1\u7406\u7684\u7406\u89e3\u6df1\u5ea6\u3002
\n \u7b54\u6848<\/p>\n
\u81ea\u52a8\u7684\u5f15\u7528\u8ba1\u6570\uff08Automatic Reference Count \u7b80\u79f0 ARC\uff09\uff0c\u662f\u82f9\u679c\u5728 WWDC 2011 \u5e74\u5927\u4f1a\u4e0a\u63d0\u51fa\u7684\u7528\u4e8e\u5185\u5b58\u7ba1\u7406\u7684\u6280\u672f\u3002<\/p>\n
\u5f15\u7528\u8ba1\u6570\uff08Reference Count\uff09\u662f\u4e00\u4e2a\u7b80\u5355\u800c\u6709\u6548\u7684\u7ba1\u7406\u5bf9\u8c61\u751f\u547d\u5468\u671f\u7684\u65b9\u5f0f\u3002\u5f53\u6211\u4eec\u521b\u5efa\u4e00\u4e2a\u65b0\u5bf9\u8c61\u7684\u65f6\u5019\uff0c\u5b83\u7684\u5f15\u7528\u8ba1\u6570\u4e3a 1\uff0c\u5f53\u6709\u4e00\u4e2a\u65b0\u7684\u6307\u9488\u6307\u5411\u8fd9\u4e2a\u5bf9\u8c61\u65f6\uff0c\u6211\u4eec\u5c06\u5176\u5f15\u7528\u8ba1\u6570\u52a0 1\uff0c\u5f53\u67d0\u4e2a\u6307\u9488\u4e0d\u518d\u6307\u5411\u8fd9\u4e2a\u5bf9\u8c61\u662f\uff0c\u6211\u4eec\u5c06\u5176\u5f15\u7528\u8ba1\u6570\u51cf 1\uff0c\u5f53\u5bf9\u8c61\u7684\u5f15\u7528\u8ba1\u6570\u53d8\u4e3a 0 \u65f6\uff0c\u8bf4\u660e\u8fd9\u4e2a\u5bf9\u8c61\u4e0d\u518d\u88ab\u4efb\u4f55\u6307\u9488\u6307\u5411\u4e86\uff0c\u8fd9\u4e2a\u65f6\u5019\u6211\u4eec\u5c31\u53ef\u4ee5\u5c06\u5bf9\u8c61\u9500\u6bc1\uff0c\u56de\u6536\u5185\u5b58\u3002\u7531\u4e8e\u5f15\u7528\u8ba1\u6570\u7b80\u5355\u6709\u6548\uff0c\u9664\u4e86 Objective-C \u8bed\u8a00\u5916\uff0c\u5fae\u8f6f\u7684 COM\uff08Component Object Model \uff09\u3001C++11\uff08C++11 \u63d0\u4f9b\u4e86\u57fa\u4e8e\u5f15\u7528\u8ba1\u6570\u7684\u667a\u80fd\u6307\u9488 share_prt\uff09 \u7b49\u8bed\u8a00\u4e5f\u63d0\u4f9b\u4e86\u57fa\u4e8e\u5f15\u7528\u8ba1\u6570\u7684\u5185\u5b58\u7ba1\u7406\u65b9\u5f0f\u3002<\/p>\n
\u5f15\u7528\u8ba1\u6570\u8fd9\u79cd\u5185\u5b58\u7ba1\u7406\u65b9\u5f0f\u867d\u7136\u7b80\u5355\uff0c\u4f46\u662f\u624b\u5de5\u5199\u5927\u91cf\u7684\u64cd\u4f5c\u5f15\u7528\u8ba1\u6570\u7684\u4ee3\u7801\u4e0d\u4f46\u7e41\u7410\uff0c\u800c\u4e14\u5bb9\u6613\u88ab\u9057\u6f0f\u3002\u4e8e\u662f\u82f9\u679c\u5728 2011 \u5e74\u5f15\u5165\u4e86 ARC\u3002ARC \u987e\u540d\u601d\u4e49\uff0c\u662f\u81ea\u52a8\u5e2e\u6211\u4eec\u586b\u5199\u5f15\u7528\u8ba1\u6570\u4ee3\u7801\u7684\u4e00\u9879\u529f\u80fd\u3002<\/p>\n
ARC \u7684\u60f3\u6cd5\u6765\u6e90\u4e8e\u82f9\u679c\u5728\u65e9\u671f\u8bbe\u8ba1 Xcode \u7684 Analyzer \u7684\u65f6\u5019\uff0c\u53d1\u73b0\u7f16\u8bd1\u5668\u5728\u7f16\u8bd1\u65f6\u53ef\u4ee5\u5e2e\u52a9\u5927\u5bb6\u53d1\u73b0\u5f88\u591a\u5185\u5b58\u7ba1\u7406\u4e2d\u7684\u95ee\u9898\u3002\u540e\u6765\u82f9\u679c\u5c31\u60f3\uff0c\u80fd\u4e0d\u80fd\u5e72\u8106\u7f16\u8bd1\u5668\u5728\u7f16\u8bd1\u7684\u65f6\u5019\uff0c\u628a\u5185\u5b58\u7ba1\u7406\u7684\u4ee3\u7801\u90fd\u81ea\u52a8\u8865\u4e0a\uff0c\u5e26\u7740\u8fd9\u79cd\u60f3\u6cd5\uff0c\u82f9\u679c\u4fee\u6539\u4e86\u4e00\u4e9b\u5185\u5b58\u7ba1\u7406\u4ee3\u7801\u7684\u4e66\u5199\u65b9\u5f0f\uff08\u4f8b\u5982\u5f15\u5165\u4e86 @autoreleasepool \u5173\u952e\u5b57\uff09\u540e\uff0c\u5728 Xcode \u4e2d\u5b9e\u73b0\u4e86\u8fd9\u4e2a\u60f3\u6cd5\u3002<\/p>\n
ARC \u7684\u5de5\u4f5c\u539f\u7406\u5927\u81f4\u662f\u8fd9\u6837\uff1a\u5f53\u6211\u4eec\u7f16\u8bd1\u6e90\u7801\u7684\u65f6\u5019\uff0c\u7f16\u8bd1\u5668\u4f1a\u5206\u6790\u6e90\u7801\u4e2d\u6bcf\u4e2a\u5bf9\u8c61\u7684\u751f\u547d\u5468\u671f\uff0c\u7136\u540e\u57fa\u4e8e\u8fd9\u4e9b\u5bf9\u8c61\u7684\u751f\u547d\u5468\u671f\uff0c\u6765\u6dfb\u52a0\u76f8\u5e94\u7684\u5f15\u7528\u8ba1\u6570\u64cd\u4f5c\u4ee3\u7801\u3002\u6240\u4ee5\uff0cARC \u662f\u5de5\u4f5c\u5728\u7f16\u8bd1\u671f\u7684\u4e00\u79cd\u6280\u672f\u65b9\u6848\uff0c\u8fd9\u6837\u7684\u597d\u5904\u662f\uff1a<\/p>\n
\u7f16\u8bd1\u4e4b\u540e\uff0cARC \u4e0e\u975e ARC \u4ee3\u7801\u662f\u6ca1\u6709\u4ec0\u4e48\u5dee\u522b\u7684\uff0c\u6240\u4ee5\u4e8c\u8005\u53ef\u4ee5\u5728\u6e90\u7801\u4e2d\u5171\u5b58\u3002\u5b9e\u9645\u4e0a\uff0c\u4f60\u53ef\u4ee5\u901a\u8fc7\u7f16\u8bd1\u53c2\u6570 -fno-objc-arc \u6765\u5173\u95ed\u90e8\u5206\u6e90\u4ee3\u7801\u7684 ARC \u7279\u6027\u3002<\/p>\n
\u76f8\u5bf9\u4e8e\u5783\u573e\u56de\u6536\u8fd9\u7c7b\u5185\u5b58\u7ba1\u7406\u65b9\u6848\uff0cARC \u4e0d\u4f1a\u5e26\u6765\u8fd0\u884c\u65f6\u7684\u989d\u5916\u5f00\u9500\uff0c\u6240\u4ee5\u5bf9\u4e8e\u5e94\u7528\u7684\u8fd0\u884c\u6548\u7387\u4e0d\u4f1a\u6709\u5f71\u54cd\u3002\u76f8\u53cd\uff0c\u7531\u4e8e ARC \u80fd\u591f\u6df1\u5ea6\u5206\u6790\u6bcf\u4e00\u4e2a\u5bf9\u8c61\u7684\u751f\u547d\u5468\u671f\uff0c\u5b83\u80fd\u591f\u505a\u5230\u6bd4\u4eba\u5de5\u7ba1\u7406\u5f15\u7528\u8ba1\u6570\u66f4\u52a0\u9ad8\u6548\u3002\u4f8b\u5982\u5728\u4e00\u4e2a\u51fd\u6570\u4e2d\uff0c\u5bf9\u4e00\u4e2a\u5bf9\u8c61\u521a\u5f00\u59cb\u6709\u4e00\u4e2a\u5f15\u7528\u8ba1\u6570 +1 \u7684\u64cd\u4f5c\uff0c\u4e4b\u540e\u53c8\u7d27\u63a5\u7740\u6709\u4e00\u4e2a -1 \u7684\u64cd\u4f5c\uff0c\u90a3\u4e48\u7f16\u8bd1\u5668\u5c31\u53ef\u4ee5\u628a\u8fd9\u4e24\u4e2a\u64cd\u4f5c\u90fd\u4f18\u5316\u6389\u3002<\/p>\n
\u4f46\u662f\u4e5f\u6709\u4eba\u8ba4\u4e3a\uff0cARC \u4e5f\u9644\u5e26\u6709\u8fd0\u884c\u671f\u7684\u4e00\u4e9b\u673a\u5236\u6765\u4f7f ARC \u80fd\u591f\u66f4\u597d\u7684\u5de5\u4f5c\uff0c\u4ed6\u4eec\u4e3b\u8981\u662f\u6307 weak \u5173\u952e\u5b57\u3002weak \u53d8\u91cf\u80fd\u591f\u5728\u5f15\u7528\u8ba1\u6570\u4e3a 0 \u65f6\u88ab\u81ea\u52a8\u8bbe\u7f6e\u6210 nil\uff0c\u663e\u7136\u662f\u6709\u8fd0\u884c\u65f6\u903b\u8f91\u5728\u5de5\u4f5c\u7684\u3002\u6211\u901a\u5e38\u5e76\u6ca1\u6709\u628a\u8fd9\u4e2a\u7b97\u5728 ARC \u7684\u6982\u5ff5\u5f53\u4e2d\uff0c\u5f53\u7136\uff0c\u8fd9\u66f4\u591a\u662f\u4e00\u4e2a\u6982\u5ff5\u6216\u5b9a\u4e49\u4e0a\u7684\u5206\u6b67\uff0c\u56e0\u4e3a\u9664\u5f00 weak \u903b\u8f91\u4e4b\u5916\uff0cARC \u6838\u5fc3\u7684\u4ee3\u7801\u90fd\u662f\u5728\u7f16\u8bd1\u671f\u586b\u5145\u7684\u3002<\/p>\n
\u00a0<\/p>\n
<pre><code> "“`
\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
“`” \u8003\u67e5\u70b9 \u6211\u8bb0\u5f97\u5728\u521a\u63a5\u89e6iOS\u7684\u65f6\u5019\u5bf9\u8fd9\u4e2aARC\u548cMRC\u5c31\u8ba8\u8bba\u9887\u6df1\uff0c\u8ba4\u4e3aARC\u662f […]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-42401","post","type-post","status-publish","format-standard","hentry","category-c"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/42401","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=42401"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/42401\/revisions"}],"predecessor-version":[{"id":42402,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/42401\/revisions\/42402"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=42401"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=42401"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=42401"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}