Casting a CFDictionaryRef to NSDictionary?(将 CFDictionaryRef 转换为 NSDictionary?)

本文介绍了将 CFDictionaryRef 转换为 NSDictionary?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我有代码(精简):

CFDictionaryRef *currentListingRef;
//declare currentListingRef here
NSDictionary *currentListing;
currentListing = (NSDictionary *) currentListingRef;

然后我得到错误:

非Objective-C指针类型'CFDictionaryRef *'(又名'constARC 不允许使用 struct __CFDictionary **') 到 'NSDictionary *'

Cast of a non-Objective-C pointer type 'CFDictionaryRef *' (aka 'const struct __CFDictionary **') to 'NSDictionary *' is disallowed with ARC

我做错了什么?如何从 CFDictionaryRef 转换为 NSDictionary?

What am I doing wrong? How do I convert from a CFDictionaryRef to an NSDictionary?

推荐答案

ARC 改变了桥接的工作方式.

ARC changed the way bridging works.

NSDictionary *original = [NSDictionary dictionaryWithObject:@"World" forKey:@"Hello"];
CFDictionaryRef dict = (__bridge CFDictionaryRef)original;
NSDictionary *andBack = (__bridge NSDictionary*)dict;
NSLog(@"%@", andBack);

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