NSUserDefaults日志中的错误

Question

我在日志中收到一些错误消息

 [User Defaults] Failed to write value for key GameId in CFPrefsPlistSource<0x1740faf00> (Domain: xxx.xxxxxx, User: kCFPreferencesCurrentUser, ByHost: No, Container: (null)): Path not accessible, switching to read-only
[User Defaults] attempt to set <private> for key in <private> in read-only (due to a previous failed write) preferences domain CFPrefsPlistSource<0x1740faf00> (Domain: xxx.xxxxxx, User: kCFPreferencesCurrentUser, ByHost: No, Container: (null))

是什么导致这个？

这就是我的用法NSUserDefaults:

- (NSString *)gameId
{
    if (_gameId)
        return _gameId;

    _gameId = [[NSUserDefaults standardUserDefaults] objectForKey:@"GameId"];
    return _gameId;
}

- (void)setGameId:(NSString *)aGameId
{
    _gameId = aGameId;
    [[NSUserDefaults standardUserDefaults] setObject:_gameId forKey:@"GameId"];
    [[NSUserDefaults standardUserDefaults] synchronize];
}

Answer 1

很多人在Xcode 8上发现了这个问题.

"虽然听起来很疯狂,但尝试重新启动手机和主机,有时Xcode会因为总和原因而卡住,只有重新启动有帮助.

使用Xcode 8.1 Beta构建,您将看到相同的警告,但您也将获得该值."

参考:https://forums.developer.apple.com/thread/51348