Using '<%# Eval("item") %>'; Handling Null Value and showing 0 against

Question

If dataitem is Null I want to show 0

<asp:Label ID="Label18" Text='<%# Eval("item") %>' runat="server"></asp:Label>

How can I accomplish this?

Jason Snelders · Accepted Answer · 2014-04-10T22:09:50.370

69

You can also create a public method on the page then call that from the code-in-front.

e.g. if using C#:

public string ProcessMyDataItem(object myValue)
{
  if (myValue == null)
  {
     return "0 value";
  }

  return myValue.ToString();
}

Then the label in the code-in-front will be something like:

<asp:Label ID="Label18" Text='<%# ProcessMyDataItem(Eval("item")) %>' runat="server"></asp:Label>

Sorry, haven't tested this code so can't guarantee I got the syntax of "<%# ProcessMyDataItem(Eval("item")) %>" entirely correct.

edited Apr 10 '14 at 22:09

answered Dec 30 '09 at 12:14

Jason Snelders

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9

I did the check in the <%# %> tags and == null didn't identify the null returns; I had to use == DBNull.Value. – user467384 Jul 16 '13 at 20:31
Where would I add that to my code here: http://stackoverflow.com/questions/27237555/why-empty-cell-throws-an-error-during-sql-stored-procedure-execution – SearchForKnowledge Dec 01 '14 at 21:33
Worth an additional check to see if myValue.ToString() is empty as well. For example, Eval("MyDate", "{0:d}") gives an empty string if MyDate is a nullable DateTime object. – Kevin Shea Mar 21 '17 at 11:34

HasanG · Answer 2 · 2016-09-12T14:20:37.557

51

I'm using this for string values:

<%#(String.IsNullOrEmpty(Eval("Data").ToString()) ? "0" : Eval("Data"))%>

You can also use following for nullable values:

<%#(Eval("Data") == null ? "0" : Eval("Data"))%>

Also if you're using .net 4.5 and above I suggest you use strongly typed data binding:

<asp:Repeater runat="server" DataSourceID="odsUsers" ItemType="Entity.User">
    <ItemTemplate>
        <%# Item.Title %>
    </ItemTemplate>
</asp:Repeater>

edited Sep 12 '16 at 14:20

answered Sep 07 '11 at 15:29

HasanG

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Won't this throw an exception if Eval("Data") is null? – KannedFarU Apr 10 '14 at 17:36
2

If the value is DBNull.Value then it won't. Example: object a = DBNull.Value; Response.Write(a.ToString()); – HasanG Apr 10 '14 at 21:43

score 13 · Answer 3 · answered Jul 02 '13 at 13:14

13

I use the following for VB.Net:

<%# If(Eval("item").ToString() Is DBNull.Value, "0 value", Eval("item")) %>

answered Jul 02 '13 at 13:14

Jonty

662
7
8

Where would I add that to my code here: http://stackoverflow.com/questions/27237555/why-empty-cell-throws-an-error-during-sql-stored-procedure-execution – SearchForKnowledge Dec 01 '14 at 21:34

score 4 · Answer 4 · edited Jan 04 '12 at 16:36

4

It should work as well

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

edited Jan 04 '12 at 16:36

COD3BOY

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answered Jan 04 '12 at 16:08

Muhammad Mudassir

124
4

score 3 · Answer 5 · answered Jan 13 '10 at 09:19

3

Moreover, you can use (x = Eval("item") ?? 0) in this case.

http://msdn.microsoft.com/en-us/library/ms173224.aspx

answered Jan 13 '10 at 09:19

Alexei Pshenichnyi

31
1

score 1 · Answer 6 · answered Jun 13 '13 at 05:32

try this code it might be useful -

<%# ((DataBinder.Eval(Container.DataItem,"ImageFilename").ToString()=="") ? "" :"<a
 href="+DataBinder.Eval(Container.DataItem, "link")+"><img
 src='/Images/Products/"+DataBinder.Eval(Container.DataItem,
 "ImageFilename")+"' border='0' /></a>")%>

score 1 · Answer 7 · answered Dec 30 '09 at 12:00

1

I don't know ASP.NET very well, but can you use the ternary operator?

http://en.wikipedia.org/wiki/Ternary_operation

Something like: (x=Eval("item")) == Null ? 0 : x

answered Dec 30 '09 at 12:00

Kristopher Ives

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score 1 · Answer 8 · answered Dec 06 '17 at 21:04

1

Used a modified version of Jason's answer:

public string ProcessMyDataItem(object myValue)
{
  if (myValue.ToString().Length < 1)
  {
     return "0 value";
  }

  return myValue.ToString();
}

answered Dec 06 '17 at 21:04

David Gauthier

11
1

score 1 · Answer 9 · answered Mar 17 '11 at 09:46

1

Use IIF.

<asp:Label ID="Label18" Text='<%# IIF(Eval("item") Is DBNull.Value,"0", Eval("item") %>' 
runat="server"></asp:Label>

answered Mar 17 '11 at 09:46

Gubi

415
2
10
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score 0 · Answer 10 · answered Dec 30 '09 at 11:58

0

Try replacing <%# Eval("item") %> with <%# If(Eval("item"), "0 value") %> (or <%# Eval("item") ?? "0 value" %>, when using C#).

answered Dec 30 '09 at 11:58

Heinzi

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I haven't tested your code, but "<%# If(Eval("item"), "0 value") %>" looks a bit odd. Not sure you can actually use an If statement with Eval like that, and wouldn't the result just be a True/False returned? – Jason Snelders Dec 30 '09 at 12:09
No, that's the VB.NET binary `If` operator: `If(value, valueIfNull)`: http://msdn.microsoft.com/en-us/library/bb513985.aspx – Heinzi Dec 30 '09 at 12:23

score 0 · Answer 11 · edited Oct 30 '15 at 16:59

0

I have tried this code and it works well for both null and empty situations :

'<%# (Eval("item")=="" || Eval("item")==null) ? "0" : Eval("item")%>'

edited Oct 30 '15 at 16:59

Alicia

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answered Feb 09 '15 at 17:30

Ziyad Godil

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score 0 · Answer 12 · answered Dec 02 '22 at 06:16

You can use the following for VB.net, especially if the value is a boolean:

<%# IIf(Eval("mydata").Equals(DBNull.Value), 0, Eval("mydata"))%>

For example, use this to automatically check or uncheck a checkbox with inline IIF eval:

<asp:CheckBox ID="mycheckbox" runat="server" Checked='<%# IIf(Eval("mydata").Equals(DBNull.Value), 0, Eval("mydata"))%>' />

The other method with .ToString will cause an error trying to convert the DBnull to a boolean.

Using '<%# Eval("item") %>'; Handling Null Value and showing 0 against

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