{"id":1385,"date":"2018-11-11T00:05:23","date_gmt":"2018-11-10T16:05:23","guid":{"rendered":"http:\/\/www.yusian.com\/blog\/?p=1385"},"modified":"2018-11-27T17:22:17","modified_gmt":"2018-11-27T09:22:17","slug":"kvo%e7%9a%84%e6%9c%ac%e8%b4%a8","status":"publish","type":"post","link":"https:\/\/www.yusian.com\/blog\/project\/2018\/11\/11\/0005231385.html","title":{"rendered":"KVO\u7684\u672c\u8d28"},"content":{"rendered":"<p>1\u3001KVO\u4e5f\u5c31\u662fkey-value-observing\uff08\u952e\u503c\u89c2\u5bdf\uff09,\u5229\u7528\u4e00\u4e2akey\u6765\u627e\u5230\u67d0\u4e2a\u5c5e\u6027\u5e76\u76d1\u542c\u5176\u503c\u5f97\u6539\u53d8\uff1b<br \/>\n1.1\u3001KVO\u7684\u4f7f\u7528\u975e\u5e38\u7b80\u5355\uff0c\u8c03\u7528\u5b9e\u4f8b\u5bf9\u8c61\u7684addObserver:forKeyPath:options:context:\u65b9\u6cd5\uff1b<br \/>\n1.2\u3001\u5bf9\u8c61\u5728\u76f8\u5173\u5c5e\u6027\u53d1\u751f\u503c\u53d8\u5316\u65f6\uff0c\u4f1a\u8c03\u7528\u89c2\u5bdf\u8005\u7684observerValueForKeyPath:ofObject:change:context\u65b9\u6cd5\uff1b<br \/>\n2\u3001\u4e3a\u4ec0\u4e48\u540c\u4e00\u4e2a\u7c7b\u521b\u5efa\u51fa\u6765\u7684\u5bf9\u8c61\uff0cKVO\u7684\u5bf9\u8c61\u5728\u4fee\u6539\u5c5e\u6027\u65f6\u4f1a\u591a\u8c03\u7528\u4e00\u4e2a\u89c2\u5bdf\u65b9\u6cd5\uff1f<br \/>\n2.1\u3001\u4ece\u5bf9\u8c61\u672c\u8d28\u6211\u4eec\u4e86\u89e3\u5230\uff0c\u6210\u5458\u5c5e\u6027\u6216\u6210\u5458\u65b9\u6cd5\u5185\u5b58\u4e2d\u4fdd\u5b58\u5728\u7c7b\u5bf9\u8c61\u4e2d\uff0c\u6240\u6709\u5b9e\u4f8b\u65b9\u6cd5\u90fd\u4e00\u6837\uff1b<br \/>\n2.2\u3001\u65e2\u7136\u540c\u4e00\u4e2a\u7c7b\u4e0b\u7684\u5b9e\u4f8b\u5bf9\u8c61\u8c03\u7528\u540c\u4e00\u4e2a\u65b9\u6cd5\u6267\u884c\u4e86\u4e0d\u540c\u7684\u52a8\u4f5c\uff0c\u5f88\u6709\u53ef\u80fd\u8fd9\u4e24\u4e2a\u5b9e\u4f8b\u5bf9\u8c61\u7684\u7c7b\u5bf9\u8c61\u4e0d\u4e00\u6837\uff1b<br \/>\n2.3\u3001\u901a\u8fc7\u8fd0\u884c\u65f6\u673a\u5236\u4e2d\u7684object_getClass()\u65b9\u6cd5\u53ef\u4ee5\u9a8c\u8bc1\u7c7b\u5bf9\u8c61\u540d\u4e3aNSKVONotifying_xxxx;<br \/>\n2.4\u3001\u7136\u800c\u4f7f\u7528\u5b9e\u4f8b\u5bf9\u8c61\u7684class\u65b9\u6cd5\u5f97\u5230\u7684\u5e76\u4e0d\u662f\u8fd9\u4e2a\u503c<br \/>\n3\u3001\u83b7\u53d6\u5f53\u524d\u7c7b\u5bf9\u8c61\u7684\u65b9\u6cd5\u5b9e\u73b0<br \/>\n3.1\u3001\u76f8\u5173\u4ee3\u7801<\/p>\n<pre lang=\"objc\" line=\"1\">- (void)methods\r\n{\r\n    unsigned int count;\r\n    Method *methods = class_copyMethodList(object_getClass(self), &count);\r\n    NSMutableArray *methodArray = [NSMutableArray array];\r\n    for (int i = 0; i < count; i++) {\r\n        SEL sel = method_getName(methods[i]);\r\n        [methodArray addObject:NSStringFromSelector(sel)];\r\n    }\r\n    NSLog(@\"%@\", methodArray);\r\n}<\/pre>\n<p>3.2\u3001\u8c03\u7528\u6709KVO\u5bf9\u8c61\u7684methods\u65b9\u6cd5\u53ef\u4ee5\u5f97\u5230\u4ed6\u91cd\u5199\u4e86\u5c5e\u6027\u7684set\u65b9\u6cd5\u3001class\u65b9\u6cd5\u3001dealloc\u65b9\u6cd5\uff1b<br \/>\n3.3\u3001\u901a\u8fc7superclass\u53ef\u4ee5\u9a8c\u8bc1NSKVONotifying_xxxx\u662f\u539f\u6709\u7c7b\u5bf9\u8c61\u7684\u5b50\u7c7b\uff1b<br \/>\n3.4\u3001\u8c03\u7528\u5b9e\u4f8b\u5bf9\u8c61\u7684methodForSelector:\u65b9\u6cd5\u53ef\u4ee5\u9a8c\u8bc1KVO\u5bf9\u8c61set\u65b9\u6cd5\u7684\u5b9e\u73b0\u4e3a_NSSetFloatValueAndNotify()\u51fd\u6570\uff1b<br \/>\n3.5\u3001_NSSetFloatValueAndNotify()\u51fd\u6570\u4e2d\u5b9e\u73b0\u5206\u522b\u8c03\u7528\uff1a<br \/>\nwillChangeValueForKey:<br \/>\nset\u65b9\u6cd5<br \/>\ndidChangeValueForKey:<br \/>\n\u5176\u4e2ddidChangeValueForKey:\u65b9\u6cd5\u4e2d\u8c03\u7528\u4e86\u76d1\u542c\u65b9\u6cd5\uff0c\u53ef\u91cd\u5199\u7c7b\u4e2d\u7684\u8be5\u4e09\u4e2a\u65b9\u6cd5\uff0c\u6253\u5370\u9a8c\u8bc1\uff1b<br \/>\n4\u3001\u603b\u7ed3\uff1a<br \/>\n4.1\u3001\u53c2\u8003\uff1a<a href=\"http:\/\/www.yusian.com\/blog\/article\/2018\/11\/10\/215619.html\" rel=\"noopener\" target=\"_blank\">Objective-C\u4e2d\u5bf9\u8c61\u7684\u5206\u7c7b\u4e0e\u672c\u8d28(isa&superclass)<\/a><br \/>\n4.2\u3001KVO\u7684\u672c\u8d28\u662f\u5728\u8fd0\u884c\u65f6\u4fee\u6539\u539f\u5b9e\u4f8b\u5bf9\u8c61\u7684isa\u6307\u9488\uff0c\u4f7f\u5176\u6307\u5411\u4e00\u4e2a\u65b0\u7684\u7c7b\u5bf9\u8c61\uff0c\u8be5\u7c7b\u5bf9\u8c61\u662f\u539f\u7c7b\u5bf9\u8c61\u7684\u5b50\u7c7b\uff1b<br \/>\n4.2\u3001\u7c7b\u5bf9\u8c61\u4e2d\u91cd\u5199\u4e86\u89c2\u5bdf\u5c5e\u6027\u7684set\u65b9\u6cd5\u3001class\u65b9\u6cd5\u3001dealloc\u65b9\u6cd5\uff1b<br \/>\n4.3\u3001\u7c7b\u5bf9\u8c61\u4e2dset\u65b9\u6cd5\u7684\u5b9e\u73b0\u5b9e\u8d28\u4e0a\u4e3aFoundation\u4e2d\u7684_NSSetFloatValueAndNotify()\u51fd\u6570\uff1b<br \/>\n4.4\u3001\u7c7b\u5bf9\u8c61\u4e2d\u91cd\u5199\u7684set\u65b9\u6cd5\u4e0d\u4ec5\u5b9e\u73b0\u4e86set\u65b9\u6cd5\u672c\u8eab\uff0c\u8fd8\u8c03\u7528\u4e86\u89c2\u5bdf\u65b9\u6cd5\u8fbe\u5230\u76d1\u542c\u7684\u76ee\u7684\uff1b<br \/>\n4.5\u3001\u53ef\u901a\u8fc7runtime\u4e2d\u7684object_getClass()\u3001class_getSuperclass()\u53caisa\u3001superclass\u5c5e\u6027\u7b49\u9a8c\u8bc1\u76f8\u5173\u7ed3\u8bba\uff1b<br \/>\n4.6\u3001\u8fd8\u53ef\u91cd\u5199willChangeValueForKey:\u3001didChangeValueForKey:\u7b49\u65b9\u6cd5\u6765\u9a8c\u8bc1\u8c03\u7528\u987a\u5e8f\uff1b<br \/>\n4.7\u3001\u53ef\u4ee5lldb\u8c03\u8bd5\u4e2d\u4f7f\u7528thread backtrack\u547d\u4ee4\u67e5\u770bset\u65b9\u6cd5\u8c03\u7528\u7684\u524d\u540e\u65b9\u6cd5\u9a8c\u8bc1\uff1b<\/p>\n","protected":false},"excerpt":{"rendered":"<p>1\u3001KVO\u4e5f\u5c31\u662fkey-value-observing\uff08\u952e\u503c\u89c2\u5bdf\uff09,\u5229\u7528\u4e00\u4e2akey\u6765\u627e\u5230\u67d0\u4e2a\u5c5e\u6027\u5e76\u76d1\u542c\u5176\u503c\u5f97\u6539\u53d8\uff1b 1.1\u3001KVO\u7684\u4f7f\u7528\u975e\u5e38\u7b80\u5355\uff0c\u8c03\u7528\u5b9e\u4f8b\u5bf9\u8c61\u7684addObserver:forKeyPath:options:context:\u65b9\u6cd5\uff1b 1.2\u3001\u5bf9\u8c61\u5728\u76f8\u5173\u5c5e\u6027\u53d1\u751f\u503c\u53d8\u5316\u65f6\uff0c\u4f1a\u8c03\u7528\u89c2\u5bdf\u8005\u7684observerValueForKeyPath:ofObject:change:context\u65b9\u6cd5\uff1b 2\u3001\u4e3a\u4ec0\u4e48\u540c\u4e00\u4e2a\u7c7b\u521b\u5efa\u51fa\u6765\u7684\u5bf9\u8c61\uff0cKVO\u7684\u5bf9\u8c61\u5728\u4fee\u6539\u5c5e\u6027\u65f6\u4f1a\u591a\u8c03\u7528\u4e00\u4e2a\u89c2\u5bdf\u65b9\u6cd5\uff1f 2.1\u3001\u4ece\u5bf9\u8c61\u672c\u8d28\u6211\u4eec\u4e86\u89e3\u5230\uff0c\u6210\u5458\u5c5e\u6027\u6216\u6210\u5458\u65b9\u6cd5\u5185\u5b58\u4e2d\u4fdd\u5b58\u5728\u7c7b\u5bf9\u8c61\u4e2d\uff0c\u6240\u6709\u5b9e\u4f8b\u65b9\u6cd5\u90fd\u4e00\u6837\uff1b 2.2\u3001\u65e2\u7136\u540c\u4e00\u4e2a\u7c7b\u4e0b\u7684\u5b9e\u4f8b\u5bf9\u8c61\u8c03\u7528\u540c\u4e00\u4e2a\u65b9\u6cd5\u6267\u884c\u4e86\u4e0d\u540c\u7684\u52a8\u4f5c\uff0c\u5f88\u6709\u53ef\u80fd\u8fd9\u4e24\u4e2a\u5b9e\u4f8b\u5bf9\u8c61\u7684\u7c7b\u5bf9\u8c61\u4e0d\u4e00\u6837\uff1b 2.3\u3001\u901a\u8fc7\u8fd0\u884c\u65f6\u673a\u5236\u4e2d\u7684object_getClass()\u65b9\u6cd5\u53ef\u4ee5\u9a8c\u8bc1\u7c7b\u5bf9\u8c61\u540d\u4e3aNSKVONotifying_xxxx; 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