macos Objective-C中的正常铸造与桥梁铸造
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Normal casting vs bridge casting in Objective - C
提问by TeaCupApp
What is the different between,
有什么不同，
(CFDataRef) data
&
&
(__bridge CFDataRef) data
Xcode asked me to change it to bridge. Is that because of ARC?
Xcode 要求我将其更改为桥接。是因为ARC吗？
回答by Mike Weller
Yes, ARC needs to be given instructions when you cast between toll-free bridged types. In this case __bridgetells ARC to do nothing, so this will behave the same as the previous standard cast.
是的，当您在免费桥接类型之间进行转换时，需要向 ARC 提供说明。在这种情况下，__bridge告诉 ARC 什么都不做，所以这将与之前的标准强制转换相同。
You can read the Transitioning to ARC Release Notesfor more details on the different ways to do bridging casts.
您可以阅读过渡到 ARC 发行说明，了解有关进行桥接转换的不同方法的更多详细信息。
