Listbox show system.data.datarowview

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
      /*  if (DropDownList1.SelectedValue == DropDownList1.SelectedItem.Text)
        {
            string query = "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME="+ "DropDownList1.SelectedItem.Text+" ;
            DataTable dt = _Default.ExecuteQuery(query);
            ListBox1.Items.Clear();
            ListBox1.DataSource = dt;
            ListBox1.DataBind();

        }*/
        string query = "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='" + DropDownList1.SelectedItem.Text+"'";



        using (SqlCommand cmd = new SqlCommand(query))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                using (DataSet ds = new DataSet())
                {

                    sda.Fill(ds);


                    ListBox1.DataSource = ds.Tables[0];
                    ListBox1.DataBind();

                }

            }
        }