获取设备UUID

/**
 获取设备UUID
 @return uuid
 */
+(NSString *)getUUID {
    CFUUIDRef uuidRef = CFUUIDCreate(kCFAllocatorDefault);
    NSString * strUUID =  (NSString *)CFBridgingRelease(CFUUIDCreateString (kCFAllocatorDefault,uuidRef));
    strUUID = [strUUID stringByReplacingOccurrencesOfString:@"-" withString:@""];
    return strUUID;
}