How to populate a drop down box from a DataTable object using C#

 bind dropdownlist from datatable c#

void LoadSubject()

    { 

        DataTable  dt=new DataTable();

        dt = getDataTable(SPName: "USP_Utkarsh_Subject", objParams: new string[] { "@action" }, objValues: new object[] { "get_subject" });

        if (dt != null && dt.Rows.Count > 0)

        {

            ddlSubject.DataSource = dt;

            ddlSubject.DataValueField = dt.Columns[0].ToString();

            ddlSubject.DataValueField = dt.Columns[1].ToString();

            ddlSubject.DataBind();

            ddlSubject.Items.Insert(0, "Seelct Subject");

        }

    }

SQL query : SELECT SubjectId, SubjectName  from Utkarsh_Subject with(nolock) order by SubjectId

create proc USP_Utkarsh_Subject

 (@action varchar(20)

 )

 AS BEGIN

 IF(@action='get_subject')

 BEGIN

 SELECT SubjectId,SubjectName  from Utkarsh_Subject with(nolock) order by SubjectId

 END

 END