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NULL value

I have item template:

<ItemTemplate>
<%#
writeProcent(DataBinder.Eval(Container.DataItem,"s trosekProcentBrez")) %>
</ItemTemplate>

and function in code behind:

Protected Function writeProcent(ByVal vrednost As Decimal) As String
If vrednost = 100 Then
writeProcent = "<font color=red>-</font>"
Else
writeProcent = vrednost
End If
End Function

when I execute the page,I get an error message:

cast from type 'DBNull' to type 'Decimal' is not valid

How can I check if DataBinder.Eval is not null?

Thank you,
Simon
Nov 19 '05 #1
4 1247
simon wrote:
I have item template:

<ItemTemplate>
<%#
writeProcent(DataBinder.Eval(Container.DataItem,"s trosekProcentBrez"))
%> </ItemTemplate>

and function in code behind:

Protected Function writeProcent(ByVal vrednost As Decimal) As String
If vrednost = 100 Then
writeProcent = "<font color=red>-</font>"
Else
writeProcent = vrednost
End If
End Function

when I execute the page,I get an error message:

cast from type 'DBNull' to type 'Decimal' is not valid

How can I check if DataBinder.Eval is not null?

Thank you,
Simon


You could change the function to accept an *object* instead of a decimal.
Then you can do your typecheck inside the function.

Hans Kesting
Nov 19 '05 #2
Better check if the object is null first in your procedure and if it is, then
return empty string

"simon" wrote:
I have item template:

<ItemTemplate>
<%#
writeProcent(DataBinder.Eval(Container.DataItem,"s trosekProcentBrez")) %>
</ItemTemplate>

and function in code behind:

Protected Function writeProcent(ByVal vrednost As Decimal) As String
If vrednost = 100 Then
writeProcent = "<font color=red>-</font>"
Else
writeProcent = vrednost
End If
End Function

when I execute the page,I get an error message:

cast from type 'DBNull' to type 'Decimal' is not valid

How can I check if DataBinder.Eval is not null?

Thank you,
Simon

Nov 19 '05 #3
Hi,

thank you for your answer.
But is this really necessary?
Declaring the variable as object takes a lot of space.

I have function with 12 parameters, so all must be declared as object,
because almost all can be null?
What is than the sence of declaring, like decimal, string, integer....?

hank you,
Simon

"Hans Kesting" <ne***********@spamgourmet.com> wrote in message
news:%2****************@TK2MSFTNGP09.phx.gbl...
simon wrote:
I have item template:

<ItemTemplate>
<%#
writeProcent(DataBinder.Eval(Container.DataItem,"s trosekProcentBrez"))
%> </ItemTemplate>

and function in code behind:

Protected Function writeProcent(ByVal vrednost As Decimal) As String
If vrednost = 100 Then
writeProcent = "<font color=red>-</font>"
Else
writeProcent = vrednost
End If
End Function

when I execute the page,I get an error message:

cast from type 'DBNull' to type 'Decimal' is not valid

How can I check if DataBinder.Eval is not null?

Thank you,
Simon


You could change the function to accept an *object* instead of a decimal.
Then you can do your typecheck inside the function.

Hans Kesting

Nov 19 '05 #4
"simon" <si*********@stud-moderna.si> wrote in message
news:ex**************@TK2MSFTNGP14.phx.gbl...
Hi,

thank you for your answer.
But is this really necessary?
Declaring the variable as object takes a lot of space.

I have function with 12 parameters, so all must be declared as object,
because almost all can be null?
All 12 parameters come from a database? Do all 12 come from columns which
permit NULL?
What is than the sence of declaring, like decimal, string, integer....?
So that you don't try to add strings, or assign 1.5 to an integer.

John Saunders
hank you,
Simon

"Hans Kesting" <ne***********@spamgourmet.com> wrote in message
news:%2****************@TK2MSFTNGP09.phx.gbl...
simon wrote:
I have item template:

<ItemTemplate>
<%#
writeProcent(DataBinder.Eval(Container.DataItem,"s trosekProcentBrez"))
%> </ItemTemplate>

and function in code behind:

Protected Function writeProcent(ByVal vrednost As Decimal) As String
If vrednost = 100 Then
writeProcent = "<font color=red>-</font>"
Else
writeProcent = vrednost
End If
End Function

when I execute the page,I get an error message:

cast from type 'DBNull' to type 'Decimal' is not valid

How can I check if DataBinder.Eval is not null?

Thank you,
Simon


You could change the function to accept an *object* instead of a decimal.
Then you can do your typecheck inside the function.

Hans Kesting


Nov 19 '05 #5

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