Ios 从KeychainItem检索值

我尝试从KeyChainItem中检索字符串，其存储方式如下：

@property (nonatomic, strong) KeychainItemWrapper *account;
if (account == nil) {
  account = [[KeychainItemWrapper alloc] initWithIdentifier:@"test" accessGroup:nil]
       }

[account setObject:self.username forKey:(__bridge id)(kSecAttrAccount)];
[account setObject:@"c6a07d48aabf35b26e1623fb" forKey:(__bridge id)(kSecValueData)];

当我检索到它时，如下所示：

  KeychainItemWrapper *wrapper = [[KeychainItemWrapper alloc] initWithIdentifier:@"test" accessGroup:nil];
        self.account = wrapper;
    }

    NSString *prevUsername = [account objectForKey:(__bridge id)(kSecAttrAccount)];
    NSString *token = [account objectForKey:(__bridge id)(kSecValueData)];

我收到了NSLog的以下值（@“%@”，令牌）

如何检索保存的字符串？我做错什么了吗？

试试这个：

NSData *nameData= [account objectForKey:(__bridge id)(kSecAttrAccount)];
NSData *tokenData = [account objectForKey:(__bridge id)(kSecValueData)];

NSString *prevUsername = [[NSString alloc] initWithData:nameData encoding:NSUTF8StringEncoding];

NSString *token = [[NSString alloc] initWithData:tokenData encoding:NSUTF8StringEncoding];

NSData *nameData= [account objectForKey:(__bridge id)(kSecAttrAccount)];
NSData *tokenData = [account objectForKey:(__bridge id)(kSecValueData)];

NSString *prevUsername = [[NSString alloc] initWithData:nameData encoding:NSUTF8StringEncoding];

NSString *token = [[NSString alloc] initWithData:tokenData encoding:NSUTF8StringEncoding];