?
Solved

how do you bind dropdownlist with in edit mode with item is not in the list

Posted on 2009-05-07
3
Medium Priority
?
278 Views
Last Modified: 2013-11-08
expert: I have a asp .net C# web INSERT and EDIT Mode FormView with a dropdownlist with "make a selection" as one of the choices. The DDL is loaded from a db table list which does not include "make a selection". When user does not make a selection a NULL is inserted into the db record . However when I bring the record up and click the edit link I get error "SelectedValue which is invalid because it does not exist in the list of items". I am not sure how to fix this issue?  My code is below:
<asp:DropDownList ID="MYDdl" runat="server" AppendDataBoundItems="True"
                                        DataSourceID="MYTypeDataSource" DataTextField="car_type"    
                                        DataValueField="car_type"
                                        SelectedValue='<%# Bind("car_type") %>' Width="200px">
                                        <asp:ListItem Value="-1">--make a selection --</asp:ListItem>
                      </asp:DropDownList>
 
                  // C# code behind
                   if (MYDdl.SelectedValue == "-1")
                    {
                        e.Values["car_type"] = null;
                      
                    }

Open in new window

0
Comment
Question by:tcmmaxt
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 15

Expert Comment

by:mohan_sekar
ID: 24329154
What do you want to do -> handle the case where you get a null value from the database? Or, prevent inserting a null value in to the database?
0
 

Author Comment

by:tcmmaxt
ID: 24329243
expert: What do you want to do -> handle the case where you get a null value from the database
Yes -->handle the case where you get a null value from the database
0
 
LVL 15

Accepted Solution

by:
mohan_sekar earned 2000 total points
ID: 24329305
Ok, you got to do two things.
Set 'AppendDataBoundItems' to True for the Dropdown list. In Page_Load, add the following line
dropdownlist.items.add("Please make a selection");

Step 2: when you get a null value from the database, select the 1st item
dropdownlist.selectedindex = 0;
0

Featured Post

On Demand Webinar: Networking for the Cloud Era

Did you know SD-WANs can improve network connectivity? Check out this webinar to learn how an SD-WAN simplified, one-click tool can help you migrate and manage data in the cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

International Data Corporation (IDC) prognosticates that before the current the year gets over disbursing on IT framework products to be sent in cloud environs will be $37.1B.
The article shows the basic steps of integrating an HTML theme template into an ASP.NET MVC project
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : http://www.videocopilot.net/presets/after_shake/ All lightning effects with instructions : http://www.mediaf…
In this video, Percona Solution Engineer Rick Golba discuss how (and why) you implement high availability in a database environment. To discuss how Percona Consulting can help with your design and architecture needs for your database and infrastr…

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question