下拉列表不会填充（asp.net的C＃代码隐藏）

Question

我几天来一直在研究这个问题，并在这里和其他网站上尝试了很多建议，但没有任何运气。我有一个基于asp.net的gridview的C＃代码隐藏，我想从类中提取一个名单列表并在下拉列表中显示它们。这是我到目前为止的代码。

===================================首先，Dropdownlist的类：

    public DataTable GetList()
    {

        // Set method to execute
        _smartObject.MethodToExecute = "GetList";

        // Assign Input properties
        if (Title != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Title"], Title);
        }
        if (LastName != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["LastName"], LastName);
        }
        if (FirstName != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["FirstName"], FirstName);
        }
        if (EmailAddress != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["EmailAddress"], EmailAddress);
        }
        if (Company != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Company"], Company);
        }
        if (alias != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["alias"], alias);
        }
        if (Phone != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Phone"], Phone);
        }
        if (JobTitle != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["JobTitle"], JobTitle);
        }
        if (Manager != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Manager"], Manager);
        }
        if (ID != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["ID"], ID);
        }
        if (ContentType != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["ContentType"], ContentType);
        }
        if (Modified != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Modified"], Modified);
        }
        if (Created != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Created"], Created);
        }
        if (Author != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Author"], Author);
        }
        if (Editor != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Editor"], Editor);
        }
        if (FileLeafRef != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["FileLeafRef"], FileLeafRef);
        }
        if (ItemChildCount != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["ItemChildCount"], ItemChildCount);
        }
        if (FolderChildCount != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["FolderChildCount"], FolderChildCount);
        }

        try
        {
            SmartObjectClientServer soServer = CreateConnection();

            // Execute SmartObject
            using (soServer.Connection)
            {
                return soServer.ExecuteListDataTable(_smartObject);
            }

        }
        catch (Exception ex)
        {
            throw DisplayError(ex);
        }
        finally
        {
            ClearProperties();
        }
    }

    public DbDataReader GetList_Reader()
    {

        // Set method to execute
        _smartObject.MethodToExecute = "GetList";

        // Assign Input properties
        if (Title != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Title"], Title);
        }
        if (LastName != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["LastName"], LastName);
        }
        if (FirstName != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["FirstName"], FirstName);
        }
        if (EmailAddress != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["EmailAddress"], EmailAddress);
        }
        if (Company != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Company"], Company);
        }
        if (alias != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["alias"], alias);
        }
        if (Phone != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Phone"], Phone);
        }
        if (JobTitle != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["JobTitle"], JobTitle);
        }
        if (Manager != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Manager"], Manager);
        }
        if (ID != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["ID"], ID);
        }
        if (ContentType != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["ContentType"], ContentType);
        }
        if (Modified != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Modified"], Modified);
        }
        if (Created != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Created"], Created);
        }
        if (Author != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Author"], Author);
        }
        if (Editor != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["Editor"], Editor);
        }
        if (FileLeafRef != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["FileLeafRef"], FileLeafRef);
        }
        if (ItemChildCount != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["ItemChildCount"], ItemChildCount);
        }
        if (FolderChildCount != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetList"].InputProperties["FolderChildCount"], FolderChildCount);
        }

        try
        {
            SmartObjectClientServer soServer = CreateConnection();

            // Execute SmartObject
            using (soServer.Connection)
            {
                return soServer.ExecuteListReader(_smartObject);
            }

        }
        catch (Exception ex)
        {
            throw DisplayError(ex);
        }
        finally
        {
            ClearProperties();
        }
    }


    public DataTable GetListDynamic(string SharePointURL)
    {
        // Verify required properties

        if (SharePointURL == null)
        {
            throw new NullReferenceException("Value required for property [SharePointURL]");
        }

        // Set method to execute
        _smartObject.MethodToExecute = "GetListDynamic";

        // Assign Input properties
        if (SharePointURL != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["SharePointURL"], SharePointURL);
        }
        if (Title != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Title"], Title);
        }
        if (LastName != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["LastName"], LastName);
        }
        if (FirstName != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["FirstName"], FirstName);
        }
        if (EmailAddress != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["EmailAddress"], EmailAddress);
        }
        if (Company != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Company"], Company);
        }
        if (alias != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["alias"], alias);
        }
        if (Phone != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Phone"], Phone);
        }
        if (JobTitle != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["JobTitle"], JobTitle);
        }
        if (Manager != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Manager"], Manager);
        }
        if (ID != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["ID"], ID);
        }
        if (ContentType != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["ContentType"], ContentType);
        }
        if (Modified != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Modified"], Modified);
        }
        if (Created != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Created"], Created);
        }
        if (Author != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Author"], Author);
        }
        if (Editor != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Editor"], Editor);
        }
        if (FileLeafRef != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["FileLeafRef"], FileLeafRef);
        }
        if (ItemChildCount != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["ItemChildCount"], ItemChildCount);
        }
        if (FolderChildCount != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["FolderChildCount"], FolderChildCount);
        }

        try
        {
            SmartObjectClientServer soServer = CreateConnection();

            // Execute SmartObject
            using (soServer.Connection)
            {
                return soServer.ExecuteListDataTable(_smartObject);
            }

        }
        catch (Exception ex)
        {
            throw DisplayError(ex);
        }
        finally
        {
            ClearProperties();
        }
    }

    public DbDataReader GetListDynamic_Reader(string SharePointURL)
    {
        // Verify required properties

        if (SharePointURL == null)
        {
            throw new NullReferenceException("Value required for property [SharePointURL]");
        }

        // Set method to execute
        _smartObject.MethodToExecute = "GetListDynamic";

        // Assign Input properties
        if (SharePointURL != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["SharePointURL"], SharePointURL);
        }
        if (Title != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Title"], Title);
        }
        if (LastName != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["LastName"], LastName);
        }
        if (FirstName != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["FirstName"], FirstName);
        }
        if (EmailAddress != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["EmailAddress"], EmailAddress);
        }
        if (Company != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Company"], Company);
        }
        if (alias != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["alias"], alias);
        }
        if (Phone != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Phone"], Phone);
        }
        if (JobTitle != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["JobTitle"], JobTitle);
        }
        if (Manager != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Manager"], Manager);
        }
        if (ID != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["ID"], ID);
        }
        if (ContentType != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["ContentType"], ContentType);
        }
        if (Modified != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Modified"], Modified);
        }
        if (Created != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Created"], Created);
        }
        if (Author != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Author"], Author);
        }
        if (Editor != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["Editor"], Editor);
        }
        if (FileLeafRef != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["FileLeafRef"], FileLeafRef);
        }
        if (ItemChildCount != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["ItemChildCount"], ItemChildCount);
        }
        if (FolderChildCount != null)
        {
            SetPropertyValue(_smartObject.ListMethods["GetListDynamic"].InputProperties["FolderChildCount"], FolderChildCount);
        }

        try
        {
            SmartObjectClientServer soServer = CreateConnection();

            // Execute SmartObject
            using (soServer.Connection)
            {
                return soServer.ExecuteListReader(_smartObject);
            }

        }
        catch (Exception ex)
        {
            throw DisplayError(ex);
        }
        finally
        {
            ClearProperties();
        }
    }




    #endregion Methods

    internal DataTable GetListDynamic()
    {
        throw new NotImplementedException();
    }
}

public class MYWORKFLOW_AllUsers_properties
{
    #region Fields (22)

    private string _SharePointSiteURL;
    private string _Title;
    private string _LastName;
    private string _FirstName;
    private string _EmailAddress;
    private string _Company;
    private string _alias;
    private string _Phone;
    private string _JobTitle;
    private string _Manager;
    private int? _ID;
    private string _ContentType;
    private DateTime? _Modified;
    private DateTime? _Created;
    private string _Author;
    private string _Editor;
    private string _FileLeafRef;
    private string _ItemChildCount;
    private string _FolderChildCount;
    private FileObject _Attachment_K2_ServiceDefined;
    private HyperLinkObject _LinkToItem_K2_ServiceDefined;
    private string _Folder_K2_ServiceDefined;

    #endregion Fields

    #region Constructors (1)

    protected MYWORKFLOW_AllUsers_properties()
    {
    }

    #endregion Constructors



}

#region Object Classes

#endregion

}

=============== ASPX =============================== =======================

==========================================代码背后=== ================

    public void ddlusers(object sender, EventArgs e)
    {
        MYWORKFLOW_AllUsers allusers = new MYWORKFLOW_AllUsers();

        DataTable dt = allusers.GetList();
        ddlAllUsers.DataSource = dt;
        ddlAllUsers.DataTextField = "userName";
        ddlAllUsers.DataValueField = "EmailAddress";
        ddlAllUsers.DataBind();


    }

    private object MYWORKFLOW_AllUsers()
    {
        throw new NotImplementedException();
    }

非常感谢任何建议。非常感谢你！