c# - WCF 服务操作总是返回 false

Question

我遇到了 WCF 服务操作问题。我从数据库中获取 passwod 值，当它应该传递它时返回 false 值。我做错了什么？

public bool LogIn(string userId, string passwd)
    {
        bool prompt;
        ProgDBEntities context = new ProgDBEntities();

        IQueryable<string> haslo = (from p in context.UserEntity where p.UserID == userId select p.Passwd);


        bool passOk = String.Equals(haslo, passwd);


        if (passOk == true )
        {
            prompt = true;                
        }
        else
        {
            prompt = false;               
        }
        return prompt;
    }

Answer 1

您似乎想要将单个检索到的条目与传入的密码进行比较(而不是任何 IQueryable/IEnumerable)。为此，请尝试使用 FirstOrDefault 方法:

public bool LogIn(string userId, string passwd)
    {
        bool prompt;
        ProgDBEntities context = new ProgDBEntities();

        var haslo = (from p in context.UserEntity where p.UserID == userId select p.Passwd).FirstOrDefault();

        // No need to use String.Equals explicitly
        bool passOk = haslo == passwd;


        if (passOk == true )
        {
            prompt = true;                
        }
        else
        {
            prompt = false;               
        }
        return prompt;
    }