NSAutoreleasePool和autoreleasepool的区别

Question

NSAutoreleasePool的官方解释
ImportantIfyouuseAutomaticReferenceCounting(ARC),youcannotuseautoreleasepoolsdirectly.Instead,[e-mail],inplaceof:NSAutoreleasePool*pool=[[NSAutoreleasePoolalloc]init;
//Codebenefittingfromalocalautoreleasepool.
[poolrelease];youwouldwrite:@autoreleasepool{
//Codebenefittingfromalocalautoreleasepool.
}@autoreleasepoolblocksaremoreefficientthanusinganinstanceofNSAutoreleasePooldirectly;youcanalsousethemevenifyoudonotuseARC.xcode4.3引入ARC，release这块就有些变化，当你使用ARC，就必须将NSAutoreleasePool的地方换成@autoreleasepoolhttp://marshal.easymorse.com/archives...

Answer 1

两者的作用时间不一样。AutoReleasePool对象的写法作用于运行时，@autoreleasepool作用于编译阶段。如果要启用ARC的话，在编译阶段就需要告诉编译器启用自动引用计数管理，而不能在运行时动态添加。