GridView DropDownList column.

Sub dgv_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs) Handles dgv.RowDataBound
   If e.Row.RowState = DataControlRowState.Edit Then
     Dim md As Med = CType(e.Row.DataItem, Med)
     Dim _type As String = md.DType
     Dim ddl As DropDownList = CType(e.Row.FindControl("ddlDType"), DropDownList)
     Dim item As ListItem = ddl.Items.FindByText(_type)
     ddl.SelectedIndex = ddl.Items.IndexOf(item)
   End If
 End Sub
 
 Sub dgv_RowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs) Handles dgv.RowUpdating
   Dim row As GridViewRow = dgv.Rows(dgv.EditIndex)
   Dim list As DropDownList = CType(row.FindControl("ddlDType"), DropDownList)
   e.NewValues("DType") = list.SelectedValue
 End Sub
 
 Private Sub dgv_RowEditing(sender As Object, e As GridViewEditEventArgs) Handles dgv.RowEditing
   If Not dgv.EditIndex = -1 Then
     Try
       Dim row As GridViewRow = dgv.Rows(dgv.EditIndex)
       Dim ddl As DropDownList = CType(row.FindControl("ddlDType"), DropDownList)
       ddl.SelectedIndex = ddl.Items.IndexOf(ddl.Items.FindByText(CType(row.DataItem, Med).DType))
     Catch
     End Try
   End If
 End Sub

<asp:TemplateField  HeaderText="DType" >
    <ItemTemplate >
       <asp:Label ID="lbDT" Text='<%# Bind("DType")%>' runat="server" ></asp:Label>
    </ItemTemplate>
    <EditItemTemplate >
       <asp:DropDownList ID="ddlDType" DataSourceID="edsDDL" DataTextField="types" DataValueField="types" runat="server" ></asp:DropDownList>
    </EditItemTemplate>
</asp:TemplateField>