cocoapods引入JSONKit,编译时因为isa出现下边的报错:
Assignment to Objective-C's isa is deprecated in favor of object_setClass()
直接将JSONKit引入工程的,可修改 Build Settings中Direct usage of 'isa'解除,
但是使用cocoapods引入的,则需要在Pods中选中JSONKit下,在其Build Settings中修改Direct usage of 'isa'选项为NO才行。