通过keychaini获取ios唯一标识

1.导入 KeychainItemWrapper.h  和.m文件    需导入<Security>库

2.设置设备唯一标识值

-(void) setKeyChainValue
{
    KeychainItemWrapper *keyChainItem=[[KeychainItemWrapper
alloc]initWithIdentifier:@"TestUUID"
accessGroup:nil];
    NSString *strUUID = [keyChainItem
objectForKey:(__bridge
id)kSecValueData];
    
    NSLog(@"---%@",strUUID);
    
    if (strUUID==nil||[strUUID
isEqualToString:@""])
    {
        [keyChainItem setObject:@"TestUUID"
forKey:(__bridge
id)kSecAttrAccount];
        [keyChainItem setObject:[self
gen_uuid] forKey:(__bridge
id)kSecValueData];
    }
}

-(NSString *) gen_uuid
{
    CFUUIDRef uuid_ref=CFUUIDCreate(nil);
    CFStringRef uuid_string_ref=CFUUIDCreateString(nil, uuid_ref);
    CFRelease(uuid_ref);
    NSString *uuid=[NSString
stringWithString:(__bridge
NSString *)(uuid_string_ref)];
    CFRelease(uuid_string_ref);
    return uuid;
}