Try this
DataTable dt_ddl = new DataTable();
dt_ddl.Columns.Add("TextFeild");
dt_ddl.Columns.Add("ValueFeild");
for(int i=0;i<ddl.items.count;i++)>
{
DataRow dr = dt.NewRow();
dr[0] = ddl.Items[i].Text;
dr[1] = ddl.Items[i].Value;
dt_ddl.Rows.Add(dr);
}
GridView1.DataSource=dt_ddl;
GridView1.DataBind();
All the best