看看这个，

我们可以使用Keychain来代替NSUserDefaults类，来存储CFUUIDCreate创建的UUID。

这样我们就可以避免重新安装UUID， 即使用户卸载并重新安装，也始终为同一应用程序获得相同的UUID。

用户重置设备时将重新创建UUID。

我用SFHFKeychainUtils尝试了这种方法，它的工作就像一个魅力。

可以帮助: 使用下面的代码，它将永远是唯一的，除非你擦除(格式)你的设备。

objective - c:

选项1:这将在每次安装时更改

UIDevice *uuid = [NSUUID UUID].UUIDString;

选项2:这将是唯一的每个供应商/开发者苹果帐户

UIDevice *myDevice = [UIDevice currentDevice];
NSString *uuid = [[myDevice identifierForVendor] UUIDString];

斯威夫特5。X:

选项1:这将在每次安装时更改

let uuid = UUID().uuidString

选项2:这将是唯一的每个供应商/开发者苹果帐户

let myDevice = UIDevice.current
let uuid = myDevice.identifierForVendor?.uuidString

我们可以在ios7中使用identifierForVendor，

-(NSString*)uniqueIDForDevice
{
    NSString* uniqueIdentifier = nil;
    if( [UIDevice instancesRespondToSelector:@selector(identifierForVendor)] ) { // >=iOS 7
        uniqueIdentifier = [[[UIDevice currentDevice] identifierForVendor] UUIDString];
    } else { //<=iOS6, Use UDID of Device       
            CFUUIDRef uuid = CFUUIDCreate(NULL);
            //uniqueIdentifier = ( NSString*)CFUUIDCreateString(NULL, uuid);- for non- ARC
            uniqueIdentifier = ( NSString*)CFBridgingRelease(CFUUIDCreateString(NULL, uuid));// for ARC
            CFRelease(uuid);
         }
    }
return uniqueIdentifier;
}

——重要提示——

UDID和identifierForVendor是不同的:——

1.) On uninstalling  and reinstalling the app identifierForVendor will change.

2.) The value of identifierForVendor remains the same for all the apps installed from the same vendor on the device.

3.) The value of identifierForVendor also changes for all the apps if any of the app (from same vendor) is reinstalled.

这是我用来获取iOS 5和iOS 6,7的ID的代码:

- (NSString *) advertisingIdentifier
{
    if (!NSClassFromString(@"ASIdentifierManager")) {
        SEL selector = NSSelectorFromString(@"uniqueIdentifier");
        if ([[UIDevice currentDevice] respondsToSelector:selector]) {
            return [[UIDevice currentDevice] performSelector:selector];
        }
    }
    return [[[ASIdentifierManager sharedManager] advertisingIdentifier] UUIDString];
}

对于Swift 3.0，请使用以下代码。

let deviceIdentifier: String = (UIDevice.current.identifierForVendor?.uuidString)!
NSLog("output is : %@", deviceIdentifier)

我相信苹果公司的这一变化惹恼了很多人。我开发了一个iOS的簿记应用程序，并有一个在线服务来同步不同设备上的更改。该服务维护所有设备的数据库以及需要传播到这些设备的更改。因此，了解哪种设备是哪种设备很重要。我使用UIDevice uniqueIdentifier跟踪设备，为了它的价值，这里是我的想法。

Generate a UUID and store in user defaults? No good because this does not persist when the user deletes the app. If they install again later the online service should not create a new device record, that would waste resources on the server and give a list of devices containing the same one two or more times. Users would see more than one "Bob's iPhone" listed if they re-installed the app. Generate a UUID and store in the keychain? This was my plan, since it persists even when the app is uninstalled. But when restoring an iTunes backup to a new iOS device, the keychain is transferred if the backup is encrypted. This could lead to two devices containing the same device id if the old and new devices are both in service. These should be listed as two devices in the online service, even if the device name is the same. Generate a hash the MAC address and bundle id? This looks like the best solution for what I need. By hashing with the bundle id, the generated device id is not going to enable the device to be tracked across apps and I get a unique ID for the app+device combination.

有趣的是，苹果自己的文档提到通过计算系统Mac地址加上bundle id和版本的哈希来验证Mac App Store收据。所以这似乎是政策允许的，但是否通过应用审查我还不知道。