__bridge_transfer和ABRecordCopyValue：和ARC [英] __bridge_transfer and ABRecordCopyValue: and ARC

问题描述

我正在访问地址簿并使用此行并使用ARC进行编译：

I'm accessing the address book and have this line and am compiling using ARC:

 ABMultiValueRef phoneNums = ABRecordCopyValue(person, kABPersonPhoneProperty);

此行需要重写为：

ABMultiValueRef phoneNums = (__bridge_transfer ) ABRecordCopyValue(person, kABPersonPhoneProperty);

如果是，那么编译器是否应该生成警告？
如果没有，那么也许我不明白将ARC与核心框架结合使用。

If yes then shouldn't the compiler have generated a warning? If not then maybe I don't understand using ARC in conjunction with core framework thoroughly.

推荐答案

不，你在这种情况下不应该桥接。 ABMultiValueRef 是 CFTypeRef 。 ABRecordCopyValue 返回 CFTypeRef 。不需要桥接。

No, you should not bridge in this case. ABMultiValueRef is a CFTypeRef. ABRecordCopyValue returns a CFTypeRef. There is no bridge required.

当您在 id 和之间进行转换时，需要进行桥接转换CFTypeRef （这是 void * 的同义词）。

Bridge casting is required when you convert between id and CFTypeRef (which is a synonym for void*).

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