苹果开发 手动内存管理MRC

MRC个人总结 关键字 alloc，new,  retain，copy, release, autorelease, dealloc. 一、内存管理的规则 1）谁创建，谁释放

#import 
#import "Person.h"int main(int argc, const char * argv[]) {Person *p = [Person new];[p run];[p release];return 0;
}

2)苹果的手动内存管理采用引用计数器管理
 当一个对象创建的时候引用计数器retainCount值为1 如果需要对这个对象进行持有则需要用retain方法

#import 
#import "Person.h"int main(int argc, const char * argv[]) {Person *p = [Person new];[p run];NSLog(@"retainCount = %lu", [p retainCount]); //retainCount 值为1[p retain]; // retainCount 值为2NSLog(@"retainCount = %lu", [p retainCount]);[p release];NSLog(@"retainCount = %lu", [p retainCount]);// retainCount 值为1;[p release];//retainCount = 0 调用dealloc方法释放内存return 0;
}

下面是Person类重写了NSObject dealloc方法 注意重写时一定要调用一下［super dealloc］方法

#import "Person.h"@implementation Person- (void)run {NSLog(@"人在跑");
}- (void)dealloc {NSLog(@"对象被释放");[super dealloc];
}@end