{"id":147,"date":"2016-12-07T16:44:41","date_gmt":"2016-12-07T08:44:41","guid":{"rendered":"http:\/\/zsaber.com\/blog\/?p=147"},"modified":"2019-08-26T15:50:24","modified_gmt":"2019-08-26T07:50:24","slug":"ios-arc-%e4%b8%8b%e4%b8%8e-c-%e6%b7%b7%e7%bc%96%e9%82%a3%e4%ba%9b%e4%ba%8b%e5%84%bf","status":"publish","type":"post","link":"http:\/\/zsaber.com\/blog\/p\/147","title":{"rendered":"iOS ARC \u4e0b\u4e0e C++ \u6df7\u7f16\u90a3\u4e9b\u4e8b\u513f"},"content":{"rendered":"

\u524d\u8a00<\/h1>\n

iOS \u7684 ARC \u6a21\u5f0f\u5404\u4f4d\u5e94\u8be5\u90fd\u5f88\u719f\u4e86, \u867d\u7136\u5728\u8fd9\u4e2a Swift \u90fd\u5df2\u7ecf\u51fa\u5230 3 \u7684\u5e74\u4ee3\u518d\u6765\u63d0 ARC \u771f\u662f\u6709\u70b9\u843d\u4f0d\u4e86,
\n\u4e0d\u8fc7 ARC \u4e0b\u548c C++ \u6df7\u7f16\u65f6\u5404\u79cd\u95ee\u9898\u5012\u662f\u5f88\u5c11\u4eba\u63d0\u5230,
\n\u6b63\u597d\u8fd9\u6b21\u5c06 ZFFramework<\/a> \u8fc1\u79fb\u5230 ARC, \u987a\u4fbf\u7559\u4e2a\u6587\u8bb0\u5f55\u4e00\u4e0b<\/p>\n

PS: \u4f5c\u4e3a\u4ece C\u8279 \u64b8\u8fc7\u6765\u7684\u7334\u5b50, \u5bf9 ARC \u5176\u5b9e\u5e76\u6ca1\u6709\u62b1\u591a\u5c11\u597d\u611f, \u6bd5\u7adf\u4e0d\u50cf Java \u7684 GC \u90a3\u4e48\u65b9\u4fbf,
\n\u53c8\u4f1a\u6709\u5404\u79cd\u8bed\u6cd5\u9650\u5236, \u4e0d\u8fc7\u8fd9\u6b21\u8bd5\u4e86\u4e0b\u611f\u89c9 ARC \u8fd8\u662f\u5f88\u597d\u7528\u5f88\u6709\u610f\u4e49\u7684<\/p>\n

\u57fa\u7840<\/h1>\n

\u4e2a\u4eba\u503e\u5411\u4e8e\u7b80\u5355\u4e00\u53e5\u8bdd\u7406\u89e3\u4e3a "\u6709\u6307\u9488\u6307\u5411, \u5219\u4fdd\u6301\u5bf9\u8c61\u7684 retain \u72b6\u6001"<\/p>\n

\u6559\u79d1\u4e66\u5f0f\u7684\u6559\u7a0b\u4ec0\u4e48\u7684\u6700\u6ca1\u52b2\u4e86, \u8fd9\u91cc\u5c31\u7b80\u5355\u5217\u4e00\u4e9b\u4e0d\u90a3\u4e48\u5bb9\u6613\u770b\u5230\u7684\u60c5\u51b5<\/p>\n

\u975e property \u6307\u9488<\/h2>\n
static MyObject *_instance = nil;\n\n@implementation MyHolder\n- (id)init\n{\n    self = [super init];\n    _instance = [MyObject new];\n    return self;\n}\n- (void)cleanup\n{\n    _instance = nil;\n}\n- (void)dealloc\n{\n    _instance = nil;\n}\n@end<\/code><\/pre>\n
\u5728 ARC \u4e0b, \u975e property \u6307\u9488\u53ef\u4ee5\u89c6\u4e3a\u548c property \u7684\u884c\u4e3a\u5b8c\u5168\u4e00\u81f4, new\/alloc \u4e4b\u540e\u76f4\u63a5\u8d4b\u503c, \u8981\u9500\u6bc1\u65f6\u8bbe\u4e3a nil \u5373\u53ef<\/p>\n
readonly property<\/h2>\n
\/\/ in *.h file\n@interface MyObject : NSObject\n@property (nonatomic, strong, readonly) id myValue;\n@end\n\n\/\/ in *.m file\n@interface MyObject()\n@property (nonatomic, strong, readwrite) id myValue;\n@end<\/code><\/pre>\n
\u8fd9\u4e2a ARC\/MRC \u4e0b\u90fd\u53ef\u4ee5\u7528\u8fd9\u79cd\u8bbe\u8ba1, ARC \u4e0b\u66f4\u662f\u4ec0\u4e48\u90fd\u4e0d\u7528\u7ba1,
\n\u4e0d\u7ba1\u662f self.myValue<\/code> \u8fd8\u662f self->_myValue<\/code> \u90fd\u53ef\u4ee5\u76f4\u63a5\u8d4b\u503c,
\n\u8fd8\u662f\u5f88\u597d\u7528\u7684<\/p>\n
\u663e\u5f0f retain<\/h2>\n
\u5076\u5c14\u4e00\u4e9b\u4ee3\u7801\u903b\u8f91\u8fd8\u662f\u5e0c\u671b\u80fd\u591f\u660e\u786e\u7684\u8868\u793a "\u6211\u60f3\u8981 retain \u8fd9\u4e2a\u5bf9\u8c61",
\n\u7136\u800c ARC \u4e0d\u8ba9\u4f60\u5e72, \u8fd9\u65f6\u5019\u53ef\u4ee5\u7528\u4e2a\u7b80\u5355\u7c97\u66b4\u7684\u65b9\u5f0f, \u5c31\u662f\u5728\u5bf9\u8c61\u91cc\u5f04\u4e2a strong property \u6765\u5b58\u81ea\u5df1,
\n\u9700\u8981\u663e\u5f0f\u91ca\u653e\u65f6\u7f6e\u7a7a\u5c31\u597d<\/p>\n
performSelector<\/h2>\n
\u8fd9\u4e2a\u95ee\u9898\u5e94\u8be5\u4e5f\u5bb9\u6613\u78b0\u5230, \u5230\u5904\u641c\u7d22\u4e00\u4e0b\u4e5f\u6709\u5404\u79cd\u89e3\u51b3\u65b9\u6848, \u56e0\u4e3a\u6bd4\u8f83\u91cd\u8981\u8fd9\u8fb9\u4e5f\u5217\u4e00\u4e0b<\/p>\n
\u539f\u56e0: \u975e\u663e\u793a\u58f0\u660e\u7684 selector, ARC \u65e0\u6cd5\u5224\u65ad\u8fd4\u56de\u503c\u662f\u5426\u9700\u8981\u81ea\u52a8 release<\/p>\n
\u95ee\u9898\u4f8b\u5b50:<\/p>\n
- (id)func1\n{\n    return [MyObject new];\n}\n- (id)func2\n{\n    return [MyObject sharedInstance];\n}\n\n\/\/ \u6b64\u5904 ARC \u65e0\u6cd5\u77e5\u9053\u8fd4\u56de\u503c\u662f\u5426\u9700\u8981\u91ca\u653e, \u56e0\u6b64\u4f1a\u62a5\u8b66\u544a\nSEL action = (someCond ? @selector(func1) : @selector(func2));\n[target performSelector:action];\n\n\/\/ \u6b64\u5904\u7f16\u8bd1\u5668\u53ef\u4ee5\u81ea\u884c\u63a8\u5bfc\u51fa\u6765, \u56e0\u6b64\u6ca1\u6709\u95ee\u9898\n[target performSelector:@selector(func1)];\n[target performSelector:@selector(func2)];<\/code><\/pre>\n
\u7f51\u4e0a\u5404\u79cd\u89e3\u51b3\u65b9\u6848\u5927\u591a\u662f\u8ba9\u4f60\u4eec\u7528\u5404\u79cd\u8def\u5b50\u7ed5\u8fc7\u7f16\u8bd1\u5668\u8b66\u544a, \u5b9e\u9645\u4e0a\u662f\u4e0d\u9760\u8c31\u7684\u65b9\u6848,
\n\u56e0\u4e3a\u76f8\u5f53\u4e8e\u8ba9 ARC \u4e0d\u8981\u5904\u7406\u8fd4\u56de\u503c, \u56e0\u6b64\u4e0a\u8ff0\u4f8b\u5b50\u7684 func1 \u5c31\u4f1a\u9020\u6210\u5185\u5b58\u6cc4\u9732\u4e86<\/p>\n
\u4e2a\u4eba\u5efa\u8bae\u7684\u65b9\u6cd5\u662f, \u975e\u5fc5\u987b\u60c5\u51b5\u4e0b\u5c31\u4e0d\u8981\u7528 selector \u8fd4\u56de\u503c\u4e86, \u786e\u5b9e\u8981\u8fd4\u56de, \u53ef\u4ee5\u7528\u53c2\u6570\u6765\u8f93\u51fa, \u6bd4\u5982<\/p>\n
@interface Holder : NSObject\n@property (nonatomic, strong) MyObject *result;\n@end\n\n- (void)func:(Holder *)result\n{\n    result.result = xxx;\n}<\/code><\/pre>\n
\u4e0e C++ \u6df7\u7f16<\/h1>\n
\u57fa\u672c\u4e0a\u5c31\u662f\u4ee5\u4e0b\u4e09\u4e2a\u5173\u952e\u8bcd\u8f6c\u6765\u8f6c\u53bb:<\/p>\n