{"id":247,"date":"2026-09-06T00:43:56","date_gmt":"2026-09-05T16:43:56","guid":{"rendered":"https:\/\/www.ziliaochi.cn\/index.php\/2026\/09\/06\/interview-ios-core\/"},"modified":"2026-09-06T00:43:56","modified_gmt":"2026-09-05T16:43:56","slug":"interview-ios-core","status":"publish","type":"post","link":"https:\/\/www.ziliaochi.cn\/index.php\/2026\/09\/06\/interview-ios-core\/","title":{"rendered":"iOS \u9762\u8bd5\u9ad8\u9891 25 \u95ee\uff1aRuntime\u3001RunLoop\u3001\u5185\u5b58\u7ba1\u7406\u4e0e SwiftUI"},"content":{"rendered":"
\n
\u5173\u952e\u8bcd<\/span>iOS \u9762\u8bd5\u3001Objective-C Runtime\u3001\u6d88\u606f\u8f6c\u53d1\u3001RunLoop\u3001ARC\u3001SwiftUI<\/div>\n
\n
\u76ee\u5f55<\/div>\n
    \n
  1. \u4e00\u3001Runtime\uff1aObjective-C \u7684\u52a8\u6001\u6027\u4ece\u54ea\u6765<\/a><\/li>\n
  2. \u4e8c\u3001\u5185\u5b58\u7ba1\u7406\uff1aARC \u5230\u5e95\u505a\u4e86\u4ec0\u4e48<\/a><\/li>\n
  3. \u4e09\u3001RunLoop\uff1a\u4e8b\u4ef6\u5faa\u73af\u7684\u9aa8\u67b6<\/a><\/li>\n
  4. \u56db\u3001Block \u4e0e GCD<\/a><\/li>\n
  5. \u4e94\u3001SwiftUI\uff1a2026 \u5e74\u7684\u5fc5\u8003\u533a<\/a><\/li>\n
  6. \u516d\u3001\u5c0f\u7ed3<\/a><\/li>\n<\/ol>\n<\/div>\n

    iOS \u9762\u8bd5\u7684\u539f\u7406\u9898\u6709\u51e0\u4e2a”\u7ecf\u5178\u5f97\u4e0d\u80fd\u518d\u7ecf\u5178”\u7684\u8003\u70b9\uff1aRuntime\u3001RunLoop\u3001\u5185\u5b58\u7ba1\u7406\uff08ARC\uff09\u3001Block\u3001\u54cd\u5e94\u94fe\u3001SwiftUI<\/strong>\u3002\u8fd9\u4e9b\u5e38\u5e74\u4e0d\u53d8\uff0c\u4f46\u8003\u5bdf\u6df1\u5ea6\u5dee\u5f02\u6781\u5927\u2014\u2014\u540c\u6837\u95ee”weak \u7684\u5b9e\u73b0\u539f\u7406”\uff0c\u6709\u4eba\u53ea\u7b54”\u81ea\u52a8\u7f6e nil”\uff0c\u6709\u4eba\u80fd\u8bb2\u6e05 SideTable \u4e0e\u5f31\u5f15\u7528\u8868<\/strong>\u3002<\/p>\n

    \u672c\u6587\u9010\u9898\u7ed9\u51fa\u6807\u51c6\u7b54\u6cd5\u3001\u8ffd\u95ee\u9677\u9631\u548c\u90a3\u53e5”\u9762\u8bd5\u5b98\u60f3\u542c\u7684\u8bdd”\u3002\u7248\u672c\u80cc\u666f\uff1aiOS 27 \u5904\u4e8e\u53d1\u5e03\u7a97\u53e3\uff0cSwift \u4e0e SwiftUI \u7684\u8fed\u4ee3\u8282\u594f\u5df2\u8d8b\u7a33\u3002<\/p>\n

    \"\u6d88\u606f\u8f6c\u53d1\u7684\u4e09\u4e2a\u9636\u6bb5\"
    OC \u6d88\u606f\u8f6c\u53d1\uff1a\u52a8\u6001\u65b9\u6cd5\u89e3\u6790 \u2192 \u5907\u63f4\u63a5\u6536\u8005 \u2192 \u5b8c\u6574\u8f6c\u53d1<\/figcaption><\/figure>\n

    \u4e00\u3001Runtime\uff1aObjective-C \u7684\u52a8\u6001\u6027\u4ece\u54ea\u6765<\/h2>\n

    Q1\uff1a\u4ec0\u4e48\u662f Runtime\uff1f\u6d88\u606f\u53d1\u9001\u7684\u5b8c\u6574\u8fc7\u7a0b\uff1f<\/h3>\n

    Objective-C \u7684\u65b9\u6cd5\u8c03\u7528\u4e0d\u662f\u76f4\u63a5\u7684\u51fd\u6570\u5730\u5740\u8df3\u8f6c\uff0c\u800c\u662f\u6d88\u606f\u53d1\u9001<\/strong>\u3002\u7f16\u8bd1\u5668\u4f1a\u628a [obj doSomething]<\/code> \u8f6c\u6210\uff1a<\/p>\n

    objc_msgSend(obj, @selector(doSomething))\n\n\/\/ \u5176\u6267\u884c\u8def\u5f84\uff08\u7b80\u5316\uff09\uff1a\n\/\/ 1. \u5feb\u901f\u67e5\u627e\uff1a\u5230 receiver \u6240\u5c5e\u7c7b\u7684 cache\uff08\u65b9\u6cd5\u7f13\u5b58\u54c8\u5e0c\u8868\uff09\u91cc\u627e IMP\n\/\/    \u2192 \u547d\u4e2d\u5219\u76f4\u63a5\u8df3\u8f6c\n\/\/ 2. \u6162\u901f\u67e5\u627e\uff1a\u7f13\u5b58\u6ca1\u547d\u4e2d\uff0c\u8d70 lookUpImpOrForward\n\/\/    \u2192 \u5728\u672c\u7c7b\u7684 method_list \u91cc\u4e8c\u5206\/\u7ebf\u6027\u67e5\u627e\n\/\/    \u2192 \u6ca1\u627e\u5230\u5219\u6cbf superclass \u94fe\u4e00\u8def\u5411\u4e0a\uff0c\u76f4\u5230 NSObject\n\/\/ 3. \u4ecd\u672a\u627e\u5230 \u2192 \u8fdb\u5165\"\u6d88\u606f\u8f6c\u53d1\"\u4e09\u9636\u6bb5<\/code><\/pre>\n
    \u5173\u952e\u70b9\uff1a\u65b9\u6cd5\u89e3\u6790\u53d1\u751f\u5728\u8fd0\u884c\u65f6\uff0c\u4e0d\u662f\u7f16\u8bd1\u65f6<\/strong>\u3002\u8fd9\u5c31\u662f OC \u52a8\u6001\u6027\u7684\u6765\u6e90\u2014\u2014\u4f60\u53ef\u4ee5\u5728\u8fd0\u884c\u65f6\u7ed9\u7c7b\u52a0\u65b9\u6cd5\u3001\u4ea4\u6362\u5b9e\u73b0\uff08Method Swizzling\uff09\u3001\u751a\u81f3\u5728\u6d88\u606f\u8f6c\u53d1\u9636\u6bb5\u628a\u6d88\u606f\u8f6c\u7ed9\u522b\u7684\u5bf9\u8c61\u3002<\/p>\n
    Q2\uff1a\u6d88\u606f\u8f6c\u53d1\u7684\u4e09\u4e2a\u9636\u6bb5\uff1f<\/h3>\n
      \n
    1. \u52a8\u6001\u65b9\u6cd5\u89e3\u6790<\/strong>\uff1a+resolveInstanceMethod:<\/code> \/ +resolveClassMethod:<\/code>\u3002\u7ed9\u4e00\u6b21\u673a\u4f1a\u52a8\u6001\u6dfb\u52a0\u65b9\u6cd5\u5b9e\u73b0<\/strong>\uff08class_addMethod<\/code>\uff09\u3002\u5e38\u7528\u4e8e @dynamic<\/code> \u5c5e\u6027\u7684\u60f0\u6027\u5b9e\u73b0\u3002<\/li>\n
    2. \u5907\u63f4\u63a5\u6536\u8005<\/strong>\uff1a-forwardingTargetForSelector:<\/code>\u3002\u8fd4\u56de\u53e6\u4e00\u4e2a\u80fd\u5904\u7406\u8be5\u6d88\u606f\u7684\u5bf9\u8c61\u3002\u8fd9\u662f\u4e09\u4e2a\u6b65\u9aa4\u91cc\u4ee3\u4ef7\u6700\u4f4e\u7684<\/strong>\uff0c\u53ea\u662f\u91cd\u5b9a\u5411\uff0c\u4e0d\u521b\u5efa NSInvocation\u3002<\/li>\n
    3. \u5b8c\u6574\u8f6c\u53d1<\/strong>\uff1a-methodSignatureForSelector:<\/code> \u8fd4\u56de\u65b9\u6cd5\u7b7e\u540d\uff0c-forwardInvocation:<\/code> \u62ff\u5230 NSInvocation<\/code> \u505a\u4efb\u610f\u5904\u7406\uff08\u8f6c\u53d1\u7ed9\u591a\u4e2a\u5bf9\u8c61\u3001\u8bb0\u5f55\u65e5\u5fd7\u3001\u541e\u6389\uff09\u3002<\/li>\n<\/ol>\n
      \/\/ \u9636\u6bb5 2\uff1a\u5feb\u901f\u8f6c\u53d1\uff08\u6027\u80fd\u6700\u597d\uff09\n- (id)forwardingTargetForSelector:(SEL)aSelector {\n    if (aSelector == @selector(heavyCompute)) {\n        return self.computeEngine;   \/\/ \u4ea4\u7ed9\u522b\u4eba\u5e72\n    }\n    return [super forwardingTargetForSelector:aSelector];\n}\n\n\/\/ \u9636\u6bb5 3\uff1a\u5b8c\u6574\u8f6c\u53d1\uff08\u53ef\u5e94\u5bf9\u672a\u5b9e\u73b0\u5d29\u6e83\u7684\u515c\u5e95\uff09\n- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector {\n    return [NSMethodSignature signatureWithObjCTypes:\"v@:\"];\n}\n- (void)forwardInvocation:(NSInvocation *)invocation {\n    NSLog(@\"\u672a\u5b9e\u73b0\u7684\u65b9\u6cd5\uff1a%@\", NSStringFromSelector(invocation.selector));\n}<\/code><\/pre>\n
      \n
      \u52a0\u5206\u70b9\uff1a\u5f88\u591a”\u9632\u5d29\u6e83”\u65b9\u6848\u5c31\u662f\u5728\u9636\u6bb5 3<\/strong> \u515c\u5e95\u3002\u4f46\u8981\u4e3b\u52a8\u8bf4\u660e\u4ee3\u4ef7\u2014\u2014NSInvocation<\/code> \u7684\u521b\u5efa\u5f00\u9500\u8f83\u5927\uff0c\u4e14\u63a9\u76d6\u95ee\u9898\u4e0d\u7b49\u4e8e\u89e3\u51b3\u95ee\u9898<\/strong>\uff0c\u7ebf\u4e0a\u5e94\u5f53\u914d\u5408\u4e0a\u62a5\uff0c\u4e0d\u80fd\u9ed8\u9ed8\u541e\u6389\u3002<\/p>\n<\/blockquote>\n
      Q3\uff1aisKindOfClass<\/code> \u548c isMemberOfClass<\/code> \u7684\u533a\u522b\uff1f<\/h3>\n
        \n
      • isKindOfClass:<\/code> \u5224\u65ad\u5bf9\u8c61\u662f\u5426\u4e3a\u8be5\u7c7b\u6216\u5176\u5b50\u7c7b\u7684\u5b9e\u4f8b<\/strong>\uff08\u6cbf\u7ee7\u627f\u94fe\u6bd4\u8f83\uff09\u3002<\/li>\n
      • isMemberOfClass:<\/code> \u53ea\u5224\u65ad\u662f\u5426\u6070\u597d\u662f\u8be5\u7c7b\u7684\u5b9e\u4f8b<\/strong>\uff08\u53ea\u6bd4\u8f83\u5f53\u524d\u7c7b\uff09\u3002<\/li>\n<\/ul>\n
        \u6709\u4e2a\u7ecf\u5178\u9677\u9631\u9898\uff1a\u5bf9\u7c7b\u5bf9\u8c61<\/strong>\u8c03\u7528\u65f6\u4f1a\u8d70\u5143\u7c7b\uff08meta class\uff09\u94fe\u3002\u7b54\u8fd9\u7c7b\u9898\u65f6\u8981\u5206\u6e05“\u5b9e\u4f8b\u65b9\u6cd5\u7248\u672c\u8d70\u7c7b\u94fe\uff0c\u7c7b\u65b9\u6cd5\u7248\u672c\u8d70\u5143\u7c7b\u94fe”<\/strong>\u3002<\/p>\n
        Q4\uff1aCategory \u548c Extension \u7684\u533a\u522b\uff1f<\/h3>\n\n\n\n\n\n\n\n\n
        \u7ef4\u5ea6<\/th>\nCategory\uff08\u5206\u7c7b\uff09<\/th>\nExtension\uff08\u6269\u5c55\/\u533f\u540d\u5206\u7c7b\uff09<\/th>\n<\/tr>\n<\/thead>\n
        \u7f16\u8bd1\u65f6\u673a<\/td>\n\u8fd0\u884c\u65f6\u5408\u5e76\u8fdb\u7c7b<\/td>\n\u7f16\u8bd1\u65f6<\/td>\n<\/tr>\n
        \u80fd\u5426\u52a0\u5c5e\u6027<\/td>\n\u53ea\u80fd\u52a0\u65b9\u6cd5\u58f0\u660e\uff0c\u5c5e\u6027\u9700\u5173\u8054\u5bf9\u8c61<\/strong><\/td>\n\u53ef\u4ee5\u52a0\u5b9e\u4f8b\u53d8\u91cf\u4e0e\u5c5e\u6027<\/td>\n<\/tr>\n
        \u9700\u8981\u6e90\u7801<\/td>\n\u4e0d\u9700\u8981<\/td>\n\u9700\u8981<\/strong>\uff08\u5199\u5728 .m \u91cc\uff09<\/td>\n<\/tr>\n
        \u5178\u578b\u7528\u9014<\/td>\n\u7ed9\u7cfb\u7edf\u7c7b\u52a0\u65b9\u6cd5\u3001\u62c6\u5206\u5927\u7c7b<\/td>\n\u9690\u85cf\u79c1\u6709\u65b9\u6cd5\u4e0e\u5c5e\u6027<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
        \u8ffd\u95ee”Category \u7684\u540c\u540d\u65b9\u6cd5\u4f1a\u600e\u6837<\/strong>“\u2014\u2014\u540e\u7f16\u8bd1\u7684 Category \u4f1a”\u8986\u76d6”\u5148\u7f16\u8bd1\u7684<\/strong>\uff08\u5b9e\u9645\u662f\u65b9\u6cd5\u5217\u8868\u987a\u5e8f\u9760\u524d\uff0c\u67e5\u627e\u65f6\u5148\u547d\u4e2d\uff09\u3002\u8fd9\u4e2a\u884c\u4e3a\u662f\u4e0d\u786e\u5b9a\u7684\uff0c\u4e0d\u8981\u4f9d\u8d56\u5b83<\/strong>\u3002\u8fd9\u4e5f\u662f\u4e3a\u4ec0\u4e48\u7ed9\u7cfb\u7edf\u7c7b\u5199 Category \u65f6\u65b9\u6cd5\u540d\u5fc5\u987b\u52a0\u524d\u7f00<\/strong>\u3002<\/p>\n
        \u4e8c\u3001\u5185\u5b58\u7ba1\u7406\uff1aARC \u5230\u5e95\u505a\u4e86\u4ec0\u4e48<\/h2>\n
        Q5\uff1aARC \u4e0b\u8fd8\u6709\u5185\u5b58\u6cc4\u6f0f\u5417\uff1f<\/h3>\n
        \u6709\uff0c\u800c\u4e14\u5f88\u5e38\u89c1\u3002<\/strong>ARC \u53ea\u662f\u81ea\u52a8\u7ba1\u7406”\u5f15\u7528\u8ba1\u6570”\uff0c\u5b83\u89e3\u51b3\u4e0d\u4e86\u5faa\u73af\u5f15\u7528<\/strong>\u3002\u4e09\u7c7b\u5178\u578b\u6cc4\u6f0f\uff1a<\/p>\n
          \n
        1. \u5faa\u73af\u5f15\u7528<\/strong>\uff1a\u5bf9\u8c61\u4e92\u76f8\u5f3a\u5f15\u7528\uff0c\u6216\u5f62\u6210\u4e86\u73af\uff08A\u2192B\u2192C\u2192A\uff09\u3002<\/li>\n
        2. Block \u6355\u83b7 self<\/strong>\uff1aBlock \u5f3a\u5f15\u7528 self\uff0cself \u53c8\u6301\u6709\u8fd9\u4e2a Block\u3002<\/li>\n
        3. \u5b9a\u65f6\u5668 \/ \u901a\u77e5\u672a\u6e05\u7406<\/strong>\uff1aNSTimer<\/code>\uff08iOS 10 \u524d\u7684 target-action \u5f62\u5f0f\uff09\u5f3a\u5f15\u7528 target\uff0cNotificationCenter<\/code> \u7684 block \u5f0f\u89c2\u5bdf\u8005\u6301\u6709 self\u3002<\/li>\n<\/ol>\n
          \/\/ \u5faa\u73af\u5f15\u7528\uff1aself -> completion -> self\nself.completion = ^{\n    [self doSomething];       \/\/ Block \u5f3a\u6355\u83b7 self\n};\n\n\/\/ \u89e3\u6cd5\uff1aweak-strong dance\n__weak typeof(self) weakSelf = self;\nself.completion = ^{\n    __strong typeof(weakSelf) strongSelf = weakSelf;\n    if (!strongSelf) return;              \/\/ \u5df2\u91ca\u653e\u5219\u76f4\u63a5\u8fd4\u56de\n    [strongSelf doSomething];             \/\/ \u4fdd\u8bc1\u6267\u884c\u671f\u95f4\u4e0d\u4f1a\u88ab\u91ca\u653e\n};\n\n\/\/ NSTimer\uff1aiOS 10+ \u7528 block \u7248 API\uff0c\u907f\u514d target \u88ab\u5f3a\u5f15\u7528\nself.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 repeats:YES block:^(NSTimer *t) {\n    [weakSelf tick];\n}];\n\/\/ \u5e76\u4e14\u8981\u5728 dealloc \/ viewWillDisappear \u91cc invalidate<\/code><\/pre>\n
          Q6\uff1aweak<\/code> \u4e3a\u4ec0\u4e48\u4f1a\u5728\u5bf9\u8c61\u91ca\u653e\u540e\u81ea\u52a8\u53d8\u6210 nil\uff1f<\/h3>\n
          \u8fd9\u662f Runtime \u5c42\u9762\u7684\u4e00\u5f20\u8868\u5728\u8d77\u4f5c\u7528\u3002\u7b80\u5316\u540e\u7684\u7ed3\u6784\u662f\uff1a<\/p>\n
            \n
          • \u7cfb\u7edf\u7ef4\u62a4\u82e5\u5e72\u5f20 SideTable<\/code><\/strong>\uff08\u5168\u5c40\u54c8\u5e0c\u8868\uff0c\u6309\u5bf9\u8c61\u5730\u5740\u5206\u6876\uff0c\u5e26\u9501\u4fdd\u8bc1\u7ebf\u7a0b\u5b89\u5168\uff09\u3002<\/li>\n
          • \u6bcf\u4e2a SideTable \u91cc\u6709 weak_table_t<\/code><\/strong>\uff1a\u4ee5\u5bf9\u8c61\u5730\u5740\u4e3a key\uff0cvalue \u662f\u6240\u6709\u6307\u5411\u5b83\u7684 weak \u6307\u9488\u5730\u5740\u7684\u96c6\u5408\uff08weak_entry_t\uff09<\/strong>\u3002<\/li>\n
          • \u5bf9\u8c61\u91ca\u653e\u65f6\uff0cRuntime \u8d70 dealloc \u2192 objc_destructInstance \u2192 clearDeallocating<\/code>\uff0c\u67e5\u51fa\u8be5\u5bf9\u8c61\u5bf9\u5e94\u7684\u6240\u6709 weak \u6307\u9488\u5730\u5740\uff0c\u628a\u5b83\u4eec\u9010\u4e2a\u7f6e\u4e3a nil<\/strong>\uff0c\u7136\u540e\u4ece\u8868\u4e2d\u79fb\u9664\u8bb0\u5f55\u3002<\/li>\n<\/ul>\n
            \u6240\u4ee5 weak<\/code> \u7684\u4ee3\u4ef7\u662f\u989d\u5916\u7684\u4e00\u6b21\u67e5\u8868\u4e0e\u7f6e nil \u64cd\u4f5c<\/strong>\uff0c\u6bd4 assign<\/code>\uff08\u4e0d\u7f6e nil\uff0c\u4f1a\u4ea7\u751f\u60ac\u5782\u6307\u9488\uff09\u5b89\u5168\u4f46\u7565\u6162\u3002<\/p>\n
            Q7\uff1astrong<\/code>\u3001copy<\/code>\u3001assign<\/code>\u3001weak<\/code> \u600e\u4e48\u9009\uff1f<\/h3>\n
              \n
            • strong<\/code><\/strong>\uff1a\u9ed8\u8ba4\uff0c\u6301\u6709\u5bf9\u8c61\uff0c\u5f15\u7528\u8ba1\u6570 +1\u3002<\/li>\n
            • copy<\/code><\/strong>\uff1a\u5efa\u7acb\u4e0d\u53ef\u53d8\u526f\u672c<\/strong>\u3002NSString<\/code>\u3001NSArray<\/code>\u3001NSDictionary<\/code> \u5c5e\u6027\u5fc5\u987b\u7528 copy<\/strong>\u2014\u2014\u5426\u5219\u4e00\u4e2a NSMutableString<\/code> \u8d4b\u8fdb\u6765\u540e\uff0c\u5916\u90e8\u6539\u52a8\u4f1a\u610f\u5916\u5f71\u54cd\u5c5e\u6027\u503c\u3002<\/li>\n
            • assign<\/code><\/strong>\uff1a\u53ea\u505a\u7b80\u5355\u8d4b\u503c\uff0c\u4e0d\u7f6e nil<\/strong>\u3002\u7528\u4e8e\u57fa\u672c\u6570\u636e\u7c7b\u578b<\/strong>\uff08int\u3001CGFloat\u3001\u7ed3\u6784\u4f53\uff09\u3002\u4fee\u9970\u5bf9\u8c61\u4f1a\u4ea7\u751f\u60ac\u5782\u6307\u9488\u3002<\/li>\n
            • weak<\/code><\/strong>\uff1a\u4e0d\u6301\u6709\uff0c\u5bf9\u8c61\u91ca\u653e\u540e\u81ea\u52a8\u7f6e nil\u3002\u7528\u4e8e delegate\u3001IBOutlet \u5b50\u89c6\u56fe\u3001Block \u4e2d\u6253\u7834\u5faa\u73af\u5f15\u7528\u3002<\/li>\n<\/ul>\n
              \n
              \u9ad8\u9891\u8ffd\u95ee\uff1a”delegate \u4e3a\u4ec0\u4e48\u7528 weak \u800c\u4e0d\u7528 strong\uff1f<\/strong>“\u2014\u2014\u56e0\u4e3a\u5178\u578b\u7ed3\u6784\u662f Controller<\/code> \u6301\u6709 View<\/code>\uff0cView<\/code> \u7684 delegate<\/code> \u6307\u56de Controller<\/code>\u3002\u82e5 delegate \u662f strong\uff0c\u5c31\u5f62\u6210\u4e86\u5faa\u73af\u5f15\u7528\uff0c\u4e24\u8005\u90fd\u91ca\u653e\u4e0d\u6389\u3002<\/p>\n<\/blockquote>\n
              Q8\uff1aAutoreleasePool \u4ec0\u4e48\u65f6\u5019\u91ca\u653e\uff1f<\/h3>\n
              autorelease<\/code> \u7684\u5bf9\u8c61\u88ab\u52a0\u5165\u5f53\u524d\u7684\u81ea\u52a8\u91ca\u653e\u6c60<\/strong>\uff0c\u6c60\u5b50\u5728\u4e00\u6b21 RunLoop \u8fed\u4ee3\u7ed3\u675f\u65f6<\/strong>\uff08\u5373\u5c06\u8fdb\u5165\u4f11\u7720\u524d\uff09\u88ab pop<\/code>\uff0c\u6c60\u5185\u5bf9\u8c61\u6536\u5230\u4e00\u6b21 release<\/code>\u3002<\/p>\n
              \u5b9e\u8df5\u4e2d\u771f\u6b63\u9700\u8981\u6ce8\u610f\u7684\u662f\u5faa\u73af\u5185\u521b\u5efa\u5927\u91cf\u4e34\u65f6\u5bf9\u8c61<\/strong>\uff1a<\/p>\n
              \/\/ \u53cd\u4f8b\uff1a\u767e\u4e07\u6b21\u5faa\u73af\u4ea7\u751f\u7684\u4e34\u65f6\u5bf9\u8c61\u5806\u79ef\u5230\u5faa\u73af\u7ed3\u675f\u624d\u91ca\u653e\uff0c\u5185\u5b58\u5cf0\u503c\u98d9\u5347\nfor (int i = 0; i < 1000000; i++) {\n    NSString *s = [NSString stringWithFormat:@\"item-%d\", i];\n    \/\/ ...\n}\n\n\/\/ \u6b63\u4f8b\uff1a\u624b\u52a8\u52a0\u81ea\u52a8\u91ca\u653e\u6c60\uff0c\u53ca\u65f6\u91ca\u653e\nfor (int i = 0; i < 1000000; i++) {\n    @autoreleasepool {\n        NSString *s = [NSString stringWithFormat:@\"item-%d\", i];\n        \/\/ ...\n    }\n}<\/code><\/pre>\n
              \u4e09\u3001RunLoop\uff1a\u4e8b\u4ef6\u5faa\u73af\u7684\u9aa8\u67b6<\/h2>\n
              Q9\uff1aRunLoop \u662f\u4ec0\u4e48\uff1f\u548c\u7ebf\u7a0b\u4ec0\u4e48\u5173\u7cfb\uff1f<\/h3>\n
              RunLoop \u662f\u4e00\u4e2a\u4e8b\u4ef6\u5904\u7406\u5faa\u73af<\/strong>\uff1a\u6709\u4e8b\u4ef6\u5c31\u5904\u7406\uff0c\u6ca1\u4e8b\u4ef6\u5c31\u4f11\u7720\u3002\u6bcf\u6761\u7ebf\u7a0b\u6700\u591a\u4e00\u4e2a RunLoop\uff0c\u4e3b\u7ebf\u7a0b\u9ed8\u8ba4\u5f00\u542f\uff0c\u5b50\u7ebf\u7a0b\u9ed8\u8ba4\u4e0d\u5f00\u542f<\/strong>\uff08\u9700\u8981\u624b\u52a8 [[NSRunLoop currentRunLoop] run]<\/code> \u6216\u7528 CFRunLoopRun()<\/code>\uff09\uff0c\u4e14\u5fc5\u987b\u81f3\u5c11\u6709\u4e00\u4e2a Source\/Timer\/Observer \u624d\u80fd\u7ef4\u6301\u8fd0\u884c\u3002<\/p>\n
              \u4e00\u6b21\u5faa\u73af\u7684\u6838\u5fc3\u6d41\u7a0b\uff1a<\/p>\n
                \n
              1. \u901a\u77e5 Observer\uff1a\u5373\u5c06\u8fdb\u5165 Loop<\/li>\n
              2. \u901a\u77e5 Observer\uff1a\u5373\u5c06\u5904\u7406 Timer \/ Source0<\/li>\n
              3. \u5904\u7406 Source0\uff08\u89e6\u6478\u4e8b\u4ef6\u3001performSelector:onThread:<\/code>\uff09<\/li>\n
              4. \u82e5\u6709 Source1\uff08\u57fa\u4e8e mach port \u7684\u7aef\u53e3\u6d88\u606f\uff09\uff0c\u8df3\u5230\u7b2c 9 \u6b65<\/li>\n
              5. \u901a\u77e5 Observer\uff1a\u5373\u5c06\u4f11\u7720<\/li>\n
              6. \u4f11\u7720\u7b49\u5f85<\/strong>\uff08\u5185\u6838\u6001\uff0c\u901a\u8fc7 mach_msg \u7b49\u5f85\u5524\u9192\uff0c\u4e0d\u5360 CPU\uff09<\/li>\n
              7. \u88ab\u67d0\u4e2a\u4e8b\u4ef6\u5524\u9192\uff08Timer \u5230\u70b9\u3001Source1 \u6d88\u606f\u3001GCD \u56de\u4e3b\u7ebf\u7a0b\u7b49\uff09<\/li>\n
              8. \u5904\u7406\u5524\u9192\u65f6\u6536\u5230\u7684\u6d88\u606f\uff0c\u56de\u5230\u7b2c 2 \u6b65<\/li>\n
              9. \u901a\u77e5 Observer\uff1a\u5373\u5c06\u9000\u51fa Loop<\/li>\n<\/ol>\n
                Q10\uff1aRunLoop \u6709\u54ea\u4e9b\u5b9e\u9645\u5e94\u7528\uff1f<\/h3>\n