hi, i use raddropdownlist to get value from raddatagrid when i click cell
this my dropdownlist databind code
private void showKategori()
        {
            try
            {
                string query = "select ID_Kategori, Nama from Kategori";
                SqlDataAdapter da = new SqlDataAdapter(query, con);
                con.Open();
                DataSet ds = new DataSet();
                da.Fill(ds, "Kategori");
                ddlkat.DisplayMember = "Nama";
                ddlkat.ValueMember = "ID_Kategori";
                ddlkat.DataSource = ds.Tables["Kategori"];
                //ddlkat.Text = "Pilih Kategori";
                con.Close();
            }
            catch (Exception ex)
            {
                con.Close();
                RadMessageBox.Show(ex.Message.ToString());
            }
        }
and this my datagrid code
try
            {
                con.Open();
                SqlCommand cmd = new SqlCommand("Select a.ID_Obat,a.ID_Kategori, b.Nama,a.ID_Supplier, c.Nama, a.Nama, a.Stok, a.Harga, a.Tanggal_Kadaluarsa,a.Tanggal_Masuk From Obat a JOIN Kategori b ON a.ID_Kategori=b.ID_Kategori JOIN Supplier c ON a.ID_Supplier=c.ID_Supplier", con);
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                DataSet ds = new DataSet();
                da.Fill(ds);
                cmd.ExecuteNonQuery();
                if (ds.Tables[0].Rows.Count > 0)
                {
                    Griddataobat.DataSource = ds.Tables[0];
                    Griddataobat.Columns[0].HeaderText = "ID Obat";
                    Griddataobat.Columns[1].HeaderText = "IDKat";
                    Griddataobat.Columns[2].HeaderText = "Kategori";
                    Griddataobat.Columns[3].HeaderText = "IDSup";
                    Griddataobat.Columns[4].HeaderText = "Supplier";
                    Griddataobat.Columns[5].HeaderText = "Nama Obat";
                    Griddataobat.Columns[6].HeaderText = "Stok Obat";
                    Griddataobat.Columns[7].HeaderText = "Harga Satuan";
                    Griddataobat.Columns[8].HeaderText = "Tanggal Kadaluarsa";
                    Griddataobat.Columns[9].HeaderText = "Tanggal Obat Masuk";
                    Griddataobat.MasterGridViewTemplate.BestFitColumns();
                }
                con.Close();
            }
            catch(Exception ex)
            {
                con.Close();
                RadMessageBox.Show(ex.Message.ToString());
            }
and this my datagrid when cell is click
private void Griddataobat_CellClick(object sender, Telerik.WinControls.UI.GridViewCellEventArgs e)
        {
            txtnamaobat.Text = Griddataobat.Rows[e.RowIndex].Cells[0].Value.ToString();
            ddlkat.SelectedValue = Griddataobat.Rows[e.RowIndex].Cells[1].Value.ToString();
        }
but my raddropdownlist not change after i click rad gridview

