^符號在Objective-C中的含義是什麼？

Question

可能重複：
Caret in objective C

什麼的^符號的意思是在Objective-C？

代碼：

GreeRequestServicePopup* requestPopup = [GreeRequestServicePopup popup]; 
requestPopup.parameters = parameters; 

requestPopup.willLaunchBlock = ^(id aSender) { 
[[NSNotificationCenter defaultCenter] postNotificationName:@"request_service_popup_will_launch_block" object:nil]; 

}; 

requestPopup.didLaunchBlock = ^(id aSender) { 
[[NSNotificationCenter defaultCenter] postNotificationName:@"request_service_popup_did_launch_block" object:nil]; 
}; 

requestPopup.willDismissBlock = ^(id aSender) { 
[[NSNotificationCenter defaultCenter] postNotificationName:@"request_service_popup_will_dismiss_block" object:nil]; 
}; 

requestPopup.didDismissBlock = ^(id aSender) { 
[[NSNotificationCenter defaultCenter] postNotificationName:@"request_service_popup_did_dismiss_block" object:nil]; 
}; 

requestPopup.cancelBlock = ^(id aSender) { 
[[NSNotificationCenter defaultCenter] postNotificationName:@"request_service_popup_cancel_block" object:nil]; 
}; 

requestPopup.completeBlock = ^(id aSender) { 
[[NSNotificationCenter defaultCenter] postNotificationName:@"request_service_popup_complete_block" object:nil]; 
}; 

[self.navigationController showGreePopup:requestPopup]; 
} 

提前感謝！

Answer 1

^是一個block字面值。文字塊之後的爭執，然後花括號來表示代碼的實際肉：

|^  | (id arg) | {};   | 
|:-----------|------------:|:------------:| 
| Block  | Parameters |  Body  | 
| literal |    |    | 

塊文字解釋相當不錯here。

Answer 2

^表示塊。在這裏看到更多：http://developer.apple.com/library/ios/#documentation/cocoa/Conceptual/Blocks/Articles/00_Introduction.html

實際上，這指定了一段代碼，將在稍後執行。

Answer 3

這些是塊。你可以閱讀一個很好的介紹here。然後閱讀Blocks Programming Topics瞭解更多詳情。