ios 判断是否是越狱版本

To detect pirated users, the easiest way is to check for the presence of a SignerIdentity key in your app's Info.plist. Since advanced crackers can easily find the standard [[[NSBundle mainBundle] infoDictionary] objectForKey: @"SignerIdentity"] checks, it is best to obscure these calls using the Objective C runtime available via #import <objc/runtime.h> or use alternative equivalents.