将CFDictionaryRef转换为NSDictionary？

Question

我有代码(剥离):

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

然后我得到错误:

使用ARC禁止将非Objective-C指针类型'CFDictionaryRef*'(又名'const struct __CFDictionary**')转换为'NSDictionary*'

我究竟做错了什么？我如何从a转换CFDictionaryRef为NSDictionary？

Answer 1

ARC改变了桥接的工作方式.

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

Answer 2

在ARC中,这应该这样做:

CFDictionaryRef currentListingRef = ...;
NSDictionary *currentListing = CFBridgingRelease(currentListingRef);

这将释放CF对象并将对象的所有权转移到ARC,否则您应手动释放CF对象.