Undefined symbols for architecture i386

发一个不错的学习iOS的网站raywenderlich,就开始写例子,对于新手来说碰到问题挺多的! AFNetworking 2.0JSON的方法好像有变化! 导入以后AFNetworking 2.0就报了下面的错误! Undefined symbols for architecture i386: "_SecCertificateCopyData", referenced fro...