獲取到UUID，然後把UUID保存到KeyChain裏面。

這樣以後即使卸載APP，也可以從KeyChain中讀取回來。

但是刷機或重裝系統後uuid還是會改變。

代碼采用CFUUID+KeyChain的實現方式：

1.創建KeyChain管理類

@implementation ZZKeyChainManager

+ (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
    return [NSMutableDictionary dictionaryWithObjectsAndKeys:
            (__bridge_transfer 
 
id)kSecClassGenericPassword,(__bridge_transfer id)kSecClass,
            service, (__bridge_transfer id)kSecAttrService,
            service, (__bridge_transfer id)kSecAttrAccount,
            (__bridge_transfer id)kSecAttrAccessibleAfterFirstUnlock,(__bridge_transfer id)kSecAttrAccessible,
            nil];
}

 
+ (void)save:(NSString *)service data:(id)data {
    //Get search dictionary
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Delete old item before add new item
    SecItemDelete((__bridge_retained CFDictionaryRef)keychainQuery);
    //Add new object to search dictionary(Attention:the data format)
 

    [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge_transfer id)kSecValueData];
    //Add item to keychain with the search dictionary
    SecItemAdd((__bridge_retained CFDictionaryRef)keychainQuery, NULL);
}

+ (id)load:(NSString *)service {
    id ret = nil;
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    //Configure the search setting
    [keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge_transfer id)kSecReturnData];
    [keychainQuery setObject:(__bridge_transfer id)kSecMatchLimitOne forKey:(__bridge_transfer id)kSecMatchLimit];
    CFDataRef keyData = NULL;
    if (SecItemCopyMatching((__bridge_retained CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
        @try {
            ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge_transfer NSData *)keyData];
        } @catch (NSException *e) {
            NSLog(@"Unarchive of %@ failed: %@", service, e);
        } @finally {
        }
    }
    return ret;
}

+ (void)deleteUUID:(NSString *)service {
    NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
    SecItemDelete((__bridge_retained CFDictionaryRef)keychainQuery);
}

@end

2.創建UUID管理類

#import "ZZUUIDManager.h"

@implementation ZZUUIDManager

static NSString * const KEY_IN_KEYCHAIN = @"com.zzuuid.uuid";


+(void)saveUUID:(NSString *)uuid{
    if (uuid && uuid.length > 0) {
        [ZZKeyChainManager save:KEY_IN_KEYCHAIN data:uuid];
    }
}

+(NSString *)getUUID{
    NSString *getUDIDInKeychain = (NSString *)[ZZKeyChainManager load:KEY_IN_KEYCHAIN];
    if (!getUDIDInKeychain || [getUDIDInKeychain isEqualToString:@""] || [getUDIDInKeychain isKindOfClass:[NSNull class]]) {
        CFUUIDRef puuid = CFUUIDCreate(nil);
        CFStringRef uuidString = CFUUIDCreateString(nil, puuid );
        NSString * result = (NSString *)CFBridgingRelease(CFStringCreateCopy(NULL, uuidString));
        CFRelease(puuid);
        CFRelease(uuidString);
        getUDIDInKeychain = result;       
        [ZZKeyChainManager save:KEY_IN_KEYCHAIN data:result];
        getUDIDInKeychain = (NSString *)[ZZKeyChainManager load:KEY_IN_KEYCHAIN];
    }
    return getUDIDInKeychain;
}

+(void)deleteUUID{
    [ZZKeyChainManager deleteUUID:KEY_IN_KEYCHAIN];
}

3.導入#import "ZZUUIDManager.h"

直接獲取

 NSLog(@"---->>uuid:%@",[ZZUUIDManager getUUID]);

參考：iOS獲取UUID

獲取iOS設備UUID