objective-c - NSAutoreleasePool和autoreleasepool的区别

Question

NSAutoreleasePool的官方解释
Important If you use Automatic Reference Counting (ARC), you cannot use autorelease pools directly. Instead, you use @autoreleasepool blocks instead. For example, in place of:

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init;
// Code benefitting from a local autorelease pool.
[pool release];

you would write:

@autoreleasepool {
// Code benefitting from a local autorelease pool.
}

@autoreleasepool blocks are more efficient than using an instance of NSAutoreleasePool directly; you can also use them even if you do not use ARC.

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 @autoreleasepool

http://marshal.easymorse.com/archives...

Answer 1

兩者的作用時間不一樣。 AutoReleasePool物件的寫法作用於執行時，@autoreleasepool作用於編譯階段。如果要啟用ARC的話，在編譯階段就需要告訴編譯器啟用自動引用計數管理，而不能在執行時動態新增。

Answer 2

現在蘋果推薦都使用@autoreleasepool{},無論是否使用ARC

@autoreleasepool blocks are more efficient than using an instance of > NSAutoreleasePool directly; you can also use them even if you do not use ARC http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSAutoreleasePool_Class/Reference/Reference.html