Question

我有一个有几种方法的课。

这是我的函数映射：

    public void Connect(string SourceFile, OleDbConnection Connection, OleDbCommand Command) { zConnect(SourceFile, Connection, Command); }
    public void Tablenames2cmb(OleDbConnection Connection, ComboBox TargetComboBox) { zTablenames2cmb(Connection, TargetComboBox); }
    public void Tablenames2cmb(OleDbConnection Connection, string Exclusion, ComboBox TargetComboBox) { zTablenames2cmb(Connection, Exclusion, TargetComboBox); }
    public string GetUser(OleDbConnection Connection, OleDbCommand Command, OleDbDataReader Reader, string username) { zGetUser(Connection, Command, Reader, username); }

前3种方法编译得很好。但是字符串方法给了我一个没有回复的错误。

方法：

    private string zGetUser(OleDbConnection Connection, OleDbCommand Command, OleDbDataReader Reader, string username)
    {
        string result = "Foo";
        return result;
    }

我想我在函数映射中犯了一个愚蠢的错误，但我无法弄清楚它是什么。

Answer 1

您的方法需要返回它调用的方法的值：

public string GetUser(OleDbConnection Connection, OleDbCommand Command, OleDbDataReader Reader, string username)
{ 
   return zGetUser(Connection, Command, Reader, username); 
}

Answer 2

你可能错过了返回声明

public string GetUser(OleDbConnection Connection, OleDbCommand Command, OleDbDataReader Reader, string username) { return zGetUser(Connection, Command, Reader, username); }

Answer 3

您不从GetUser方法返回字符串。它的身体没有回报价值：

public string GetUser(OleDbConnection Connection, OleDbCommand Command, OleDbDataReader Reader, string username) 
{ 
   return zGetUser(Connection, Command, Reader, username); 
}

有时候，不那么聪明的格式会有所帮助。

String方法的C＃类构造

3 个答案: