During my postbacks, I try to assign the value from an Input tag to a
property of a custom control. However, I keep recieving the following error:


An exception of type 'System.OverflowException' occurred in
Microsoft.VisualBasic.dll but was not handled in user code
Additional information: Arithmetic operation resulted in an overflow.


The code that it highlights during this error is the 2nd line of the
following (Me.Value = postCollection(Me.ID & "_currvalue")):


Public Function LoadPostData(ByVal postDataKey As String, ByVal
postCollection As NameValueCollection) As Boolean Implements
IPostBackDataHandler.LoadPostData
Me.Value = postCollection(Me.ID & "_currvalue")
Return True
End Function


I will admit that this is my first time using the IPostBackDataHandler
interface, but 'System.OverflowException' seems like a very strange
exception for this part of my code, since I am just doing a String
concatenation and an assignment. The value associated with this
postCollection key is a positive integer (well, a string actually, but it
has no negative signs or decimal places, just a couple digits) and Me.Value
is a Property of my Control that is of type Integer, so it shouldn't have
any problem converting, right? If anybody has any ideas as to where I might
be going wrong here, or where I could look to help find the problem, I would
appreciate it. Thanks.
--
Nathan Sokalski
njsokalski (AT) hotmail (DOT) com
http://www.nathansokalski.com/

What does the Value property and RaisePostDataChanged method (another method
of IPostBackDataHandler) look like? If the code isn't long oner, post entire
control's sources.


--
Teemu Keiski
ASP.NET MVP, AspInsider
Finland, EU
http://blogs.aspadvice.com/joteke



"Nathan Sokalski" <njsokalski (AT) hotmail (DOT) com> wrote

Here is the code for the Value property:


<Description("The value that the Slider is currently set to")>
<DefaultValue("0")> _
Public Property Value() As Integer
Get
If IsNothing(ViewState("value")) Then Return 0 Else Return
ViewState("value")
End Get
Set(ByVal value As Integer)
ViewState("value") = value
End Set
End Property


And here is the code for the RaisePostDataChangedEvent method:


Public Sub RaisePostDataChangedEvent() Implements
IPostBackDataHandler.RaisePostDataChangedEvent
End Sub


The only code in my OnPreRender method other than the creating of the
client-side scripts, which I do using String concatenation and the
Page.ClientScript.RegisterClientScriptBlock method, is setting the only
global variable I have, which is declared as Private pixeltovalue As
Decimal, as follows:


Me.pixeltovalue = (Me.Width - 48) / (Me.MaxValue - Me.MinValue)


My Render method just uses the basic methods of the HtmlTextWriter class.
The only arithmetic operations in my OnPreRender and Render methods are very
simple addition, subtraction, multiplication, and division. I did not think
it was worth pasting all my code into this message (although I can if you
really think it will help you solve the problem), since almost all of it is
property declarations, all of which look exactly the same as the one above,
String concatenation while building the JavaScript functions, and the basic
HtmlTextWriter methods used to create the html tags; the only other code in
my control is the IPostBackDataHandler implementation and the
Me.pixeltovalue declaration and assignment that I showed above. Any ideas as
to what the problem might be? Thanks.
--
Nathan Sokalski
njsokalski (AT) hotmail (DOT) com
http://www.nathansokalski.com/

"Teemu Keiski" <joteke (AT) aspalliance (DOT) com> wrote

Hi,

could it be that the

Me.Value = postCollection(Me.ID & "_currvalue")

would be so big number it doesn't fit to the value? (32-bit Integer). Where
does this value come from? Is it calculated, entered by user?


--
Teemu Keiski
ASP.NET MVP, AspInsider
Finland, EU
http://blogs.aspadvice.com/joteke



"Nathan Sokalski" <njsokalski (AT) hotmail (DOT) com> wrote

No, that was not the problem, but I found that in my client-side JavaScript
I needed to explicitly convert a text value to a Number, I was ending up
with a value like "25-1" being sent to the server instead of 24, but thanks
for your help anyway.
--
Nathan Sokalski
njsokalski (AT) hotmail (DOT) com
http://www.nathansokalski.com/

"Teemu Keiski" <joteke (AT) aspalliance (DOT) com> wrote