'ddEventType' has a SelectedValue which is invalid because it does not exist in the list of items.

Question

User1018471933 posted

If my Dropdown List is connected to a SQL Datasource and i KNOW that there will be result set, then why the heck am I getting this error?

Error: Sys.WebForms.PageRequestManagerServerErrorException: 'ddEventType' has a SelectedValue which is invalid because it does not exist in the list of items.
Parameter name: value

Answer 1

User-1360095595 posted
Your code is trying to set the DDL to a value that doesn't exist. Check what you're trying to set the DDL to and check what listitems/options are in the DDL in question.

Answer 2

User-419562455 posted

please show your dropdownlist properties and sqldatasource.

Answer 3

User-419562455 posted

i hope you bind diffrent datafield in ddl valuefield.

Answer 4

User1018471933 posted

I keep getting this error now ALL over my Web App. I am not trying to set the DDL value yet, as I am simply trying to get into the Edit/Insert mode of the FormView now (where this DDL is located). It DOES have a result set (what will I do when it doesn't??) and I have even put in a Item Value to try and curb this error, but alas no luck...

 

Unless, of course, I'm being stupid here thinking that I can put a DDL into a FormView template while very likely this cannot/should not be done??

Here is the ASPX Code for this control (this portion specifically from the Edit template of this FormView):

<td width="300">
                                            <asp:DropDownList ID="ddAccTypes1" runat="server" 
                                                DataSourceID="sqlGetAccTypes1" DataTextField="TYPE_DESCRIPTION" 
                                                DataValueField="ACCOUNT_TYPE" SelectedValue='<%# Bind("ACCOUNT_TYPE") %>' 
                                                Width="200px" AppendDataBoundItems="True">
                                                <asp:ListItem>Select Account Type</asp:ListItem>
                                            </asp:DropDownList>
                                            <asp:SqlDataSource ID="sqlGetAccTypes1" runat="server" 
                                                ConnectionString="<%$ ConnectionStrings:ClubManagerRemote %>" 
                                                SelectCommand="SELECT * FROM [tblACCOUNT_TYPES] ORDER BY [TYPE_DESCRIPTION]">
                                            </asp:SqlDataSource>
                                        </td>

Answer 5

User-1360095595 posted
Yes you are trying to set the value. It's done via the selectedvalue property which you bind to account_type. So the account_type value you're getting, probably from the formview's DataSource, is returning a value which doesn't exists in the DDL based on DataSource you're binding the DDL to.

Answer 6

User1018471933 posted

Hi Metal!

I see. Could this be because the ACCOUNT_TYPE field on the FormView's Datasource actually returns a NULL/empty value?

Answer 7

User1018471933 posted

I just tested my own question on the Database and it worked. But this spawns another question:

I recently added this new field to the DB Table, which means that it will be NULL to begin with. Is there some code/tecnique I can implement that will overcome this error in future, or should I simply then make sure that a new column, or a column elsewhere that will be bound this way, has data and no NULL values, then?

 

Answer 8

User-1360095595 posted
One approach might be to change your SQL select to return say -1 if the value is null. You can use ISNULL for this. And in this case you add a generic item to your DDL with a value of -1 and a text of "Select". Alternatively, handle the formview databound event and in there check if the value is null and change the selectedvalue to the generic item. I think that will work also. You could also add the check inline, that is in the HTML markup itself.