If it is single select only use the SelectedIndexChanged property to call your server side method.

"The one language all programmers understand is profanity."

Hi,

     I tried Session way:
On Page_Load():
Dim temp1 As String
 temp1 = Session("ListBoxText")
  If CInt(temp1) <> -1 Then
    lbCurrentItems.SelectedIndex = CInt(temp1)
  End If

Private Sub listbox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles listbox1.SelectedIndexChanged

Session("ListBoxText") = listbox1.SelectedIndex
End Sub

But it is always giving error,i have tried so many ways:

Input string was not in a correct format.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.FormatException: Input string was not in a correct format.
Stack Trace:


[FormatException: Input string was not in a correct format.]
   Microsoft.VisualBasic.CompilerServices.DoubleType. Parse(String Value, NumberFormatInfo NumberFormat)
   Microsoft.VisualBasic.CompilerServices.DoubleType. Parse(String Value)
   Microsoft.VisualBasic.CompilerServices.IntegerType .FromString(String Value)

[InvalidCastException: Cast from string "" to type 'Integer' is not valid.]
   Microsoft.VisualBasic.CompilerServices.IntegerType .FromString(String Value)

Any idea?

Regards
Monica

Try this on your page load:

Dim temp1 as integer = Session("listboxtext")

If Not temp1 is Nothing AND temp1 <> -1 then
[execute if]
End if

In your listbox sub:

If listbox1.selectedIndex > -1 then
 Session("ListBoxText") = listbox1.SelectedIndex
Else
 Session("ListBoxText") = -1
End If


"The one language all programmers understand is profanity."

No effect. It is giving same error, infact earlier i had tried a slight variation of what you posted but it also met the same fate.

Ok try this:

Dim temp1 as integer = CINT(Session("listboxtext")) 'If the session variable is empty this will cast the session variable to the value of 0

or

if not Session("listboxText") is nothing then
temp1 = session("listboxtext")
end if

The above essentially checks to see if the Session variable is Null and if it isnt it will set temp1 to the value of the session variable.

"The one language all programmers understand is profanity."

Hi,

    Its hard time again. Same error. I believe in listbox1_SelectedIndexChanged all is well. I am unsure about the code what i am using in Page_Load(). Am i doing it right in Page_Load() to retrieve the session variable?

Regards
Monica

The code I supplied in the previous post should go inside your Page_Load(). What happens is, when you navigate to that page for the very first time Session("listBoxText") will be null, it wont have a value assoicated with it. What you should do in your page load method is this:

Sub Page_Load()

If Not Page.IsPostBack then
if not Session("listboxText") is nothing then
  temp1 = session("listboxtext")
  lbCurrentItems.SelectedIndex = temp1
end if
End If

End Sub

hth

"The one language all programmers understand is profanity."

Its done. The culprit was putting that code on Page_Load(). I put it where the data access is done & it worked. Thanks a lot for all your help.

Regards
Monica

No worries, glad it worked out for you in the end.

"The one language all programmers understand is profanity."