System.Data.Datarawview

Question

Hi,

I am populating dropdown into gridview.when i am running application, in dropdown it shows me this data System.Data.Datarawview.

Here I have pasted my code : 

public void FindControlInGV()

        {

            foreach (GridViewRow gvr in gvPopulate.Rows)

            {

                SqlDataAdapter ad = new SqlDataAdapter("select B_Element from Test_Table", con);

                DataSet ds = new DataSet();

                ad.Fill(ds, "Test_Table");

                DropDownList ddlSelect = new DropDownList();

                ddlSelect = (DropDownList)gvr.Cells[0].FindControl("ddlPopulate");

                ddlSelect.DataSource = ds;

                ddlSelect.DataBind();

            }

            //}

        }

I am new to asp.net pls help me out.