String []与List

Question

我有一个使用DataBase数据创建的列表。 列表中的结构是：

    public struct GetInfoForGraph
    {
        public float A { get; set; }
        public float B { get; set; }
        public DateTime Time { get; set; }
        public String Customer_name { get; set; }
        public String Type_name { get; set; }
        public String Program_name { get; set; }
        public int Id_Tbl_Program { get; set; }
        public int Id_Tbl_File_Names { get; set; }
        public string File_Name { get; set; }
    }

我在列表中添加数据如下：

public List<GetInfoForGraph> CreatesListInfoForGraphPoints()
{
    string sqlCommand = "SELECT A AS A";
    sqlCommand += ", B AS B";
    sqlCommand += ", TIME_FORMATTED AS Time";
    sqlCommand += ", CUSTOMER_NAME As Customer_name";
    sqlCommand += ", PROGRAM_NAME As Program_name";
    sqlCommand += ", TYPE_NAME As Type_name";
    sqlCommand += ", ID_TBL_PROGRAM AS Id_Tbl_Program";
    sqlCommand += ", ID_TBL_FILE_NAMES as Id_Tbl_File_Names";
    sqlCommand += ", ONLY_FILE_NAME as File_Name";
    sqlCommand += "  FROM VW_MAIN_INFO";
    sqlCommand += "  where CUSTOMER_NAME = '" + Project.CustomerName + "'";
    sqlCommand += "  and PROGRAM_NAME = '" + Project.ProgramName + "'";
    sqlCommand += "  and TYPE_NAME = '" + Project.TypeName + "'";
    sqlCommand += "  ORDER BY Time";

    List<GetInfoForGraph> DataForGraph = new List<GetInfoForGraph>();
    SqlConnection conn = new SqlConnection(@"XXXX");
    SqlCommand cmd = new SqlCommand(sqlCommand, conn);
    SqlDataReader dr;
    try
    {
        conn.Open();
        dr = cmd.ExecuteReader();
        while (dr.Read())
        {
            DataForGraph.Add(new GetInfoForGraph()
            {
                A = dr.GetFloat(dr.GetOrdinal("A")),
                B = dr.GetFloat(dr.GetOrdinal("B")),
                Time = dr.GetDateTime(dr.GetOrdinal("Time")),
                Customer_name = dr.GetString(dr.GetOrdinal("Customer_name")),
                Program_name = dr.GetString(dr.GetOrdinal("Program_name")),
                Type_name = dr.GetString(dr.GetOrdinal("Type_name")),
                Id_Tbl_Program = dr.GetInt32(dr.GetOrdinal("Id_Tbl_Program")),
                Id_Tbl_File_Names = dr.GetInt32(dr.GetOrdinal("Id_Tbl_File_Names")),
                File_Name = dr.GetString(dr.GetOrdinal("File_Name"))
            });

        }
        dr.Close();
    }

    catch (Exception ex)
    {
        ActivityLog.LogError(new StackTrace(true), ex);
    }
    finally
    {

        conn.Close();
    }

    return DataForGraph;

} // End of List<GetInfoForGraph> CreatesListInfoForGraphPoints()

我想补充一下我的＆＃34; DropDown＆＃34;事件以下信息：

• 与列表中的File_name不同

我尝试了什么： *来自Here的想法

        private void CboxReceiveNameFile_DropDown(object sender, EventArgs e)
    {

        List<int> result = DataForGraph.Select(o => o.FirstInteger).Distinct().ToList();

    }

但它给了我错误＆＃39;对象＆＃39;不包含选择和无扩展方法的定义＆＃39;选择＆＃39;接受类型＆＃39;对象＆＃39; ...

的第一个参数

有什么身体可以帮助我吗？欢迎任何帮助！谢谢