将我们的代码库转换为Swift3，我遇到了这个问题:ABAddressBookRequestAccessWithCompletion(addressBookRef){(granted:Bool,error:CFError?)inDispatchQueue.main.async{ifletnsError=errorasNSError{...}}}编译器错误是:无法转换“CFError?”类型的值？在强制中输入“NSError”更改为:ifletnsError=erroras?NSError{...}给出警告:Castfrom'CFError?'不相关的类型“NSError”总是失败