ASP.NET - Handling NULL values when using EVAL in a dropdownlist

I am selecting a value from a dropdown using this

<asp:DropDownList ID="ddlShipVia" runat="server" Width="180" Font-Names="Verdana" ForeColor="#666666" Height="21" Style="font-size:12px;" Text=<%#Eval("ShipVia")%>></asp:DropDownList>

Open in new window


Works great except when the DB value is NULL. How do I handle this?
Mike MillerSoftware EngineerAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Michael FowlerSolutions ConsultantCommented:
You can use something like this

Eval("ShipVia") == null?"0": Eval("ShipVia");

Open in new window

Mike MillerSoftware EngineerAuthor Commented:
How? Where?

<asp:DropDownList ID="ddlShipVia" runat="server" Width="180" Font-Names="Verdana" ForeColor="#666666" Height="21" Style="font-size:12px;" Text=Eval("ShipVia") == null?"0": Eval("ShipVia");></asp:DropDownList>

Open in new window

Michael FowlerSolutions ConsultantCommented:
<asp:DropDownList ID="ddlShipVia" runat="server" Width="180" Font-Names="Verdana" ForeColor="#666666" Height="21" Style="font-size:12px;" Text=<%#Eval("ShipVia") == null?"0": Eval("ShipVia")%>></asp:DropDownList>

Open in new window

Python 3 Fundamentals

This course will teach participants about installing and configuring Python, syntax, importing, statements, types, strings, booleans, files, lists, tuples, comprehensions, functions, and classes.

Mike MillerSoftware EngineerAuthor Commented:
Playing around with it but here's what your code gets me...

Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: BC30201: Expression expected.

Source Error:

Line 428:</td>
Line 429:<td align = "left" valign="top">
Line 430:<asp:DropDownList ID="ddlShipVia" runat="server" Width="180" Font-Names="Verdana" ForeColor="#666666" Height="21" Style="font-size:12px;" Text=<%#Eval("ShipVia") == null?"0": Eval("ShipVia")%>></asp:DropDownList>
Line 431:</td>
Line 432:</tr>
Mike MillerSoftware EngineerAuthor Commented:
FYI I'm using vb.net and there is a blank value in the DDL it can default to when NULL
Michael FowlerSolutions ConsultantCommented:
Sorry I do not have access to VS at the moment for my own testing. Try this
<asp:DropDownList ID="ddlShipVia" runat="server" Width="180" Font-Names="Verdana" ForeColor="#666666" Height="21" Style="font-size:12px;" Text='<%# Eval("ShipVia") == null ? "0" : Eval("ShipVia")%'>></asp:DropDownList>

Open in new window

Michael FowlerSolutions ConsultantCommented:
OK this code returns 0 when the value is null. When it is working just replace "0" with the appropiate value eg an empty string ""
Mike MillerSoftware EngineerAuthor Commented:
Just thought of something...we can't use "Text" in a dropdownlist can we?
Michael FowlerSolutions ConsultantCommented:
Michael FowlerSolutions ConsultantCommented:
I cannot test at the moment but I thought your original code was working fine unless a null value was encountered
Mike MillerSoftware EngineerAuthor Commented:
I have not been successful yet, but am not abandoning this question
Mike MillerSoftware EngineerAuthor Commented:
Text='<%# Eval("ShipVia") == null ? "0" : Eval("ShipVia")%'>

Open in new window


gets

BC36637: The '?' character cannot be used here.
Michael FowlerSolutions ConsultantCommented:
The expression is an inline if statement and so the "?" should be valid

http://msdn.microsoft.com/en-us/library/ty67wk28.aspx

Another option here would be to use code behind to achieve the same result
public string ProcessMyDataItem(object value)
{
  if (value== null)
  {
     return "";
  }
  return value.ToString();
}

Open in new window


then in the page use
Text='<%# ProcessMyDataItem(Eval("ShipVia")) %>'

Open in new window

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
ASP.NET

From novice to tech pro — start learning today.