ViewState null reference exception

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ViewState null reference exception

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jhermiz

3564 Posts

Posted - 2007-12-18 : 09:21:32

Once in a while I will get an exception like below:

I'm not sure how to handle this part


 If ViewState("ReferrerUrl").ToString Is Nothing Then
                    Response.Redirect("default.aspx?New=" & bNew & "&Sent=" & bSentMail)
                Else
                    If InStr(ViewState("ReferrerUrl").ToString().ToLower, "default.aspx") > 0 Then
                        Response.Redirect("default.aspx?New=" & bNew & "&Sent=" & bSentMail)
                    Else
                        Response.Redirect(ViewState("ReferrerUrl").ToString() & "?New=" & bNew & "&Sent=" & bSentMail)
                    End If
                End If

As I thought:

If ViewState("ReferrerUrl").ToString Is Nothing Then

Checks to see if it is null?

Weblog -- [url]http://weblogs.sqlteam.com/jhermiz[/url]

SwePeso
Patron Saint of Lost Yaks

30421 Posts

Posted - 2007-12-18 : 09:28:13

Is Empty?

E 12°55'05.25"
N 56°04'39.16"

jsmith8858
Dr. Cross Join

7423 Posts

Posted - 2007-12-18 : 09:29:58

just use:

if ViewState("ReferrerURL") Is Nothing Then ....

You cannot apply the ToString() method on a variable that is not set to an object, so if the ViewState("..") return nothing, the call to ToString() will always generate an error.

- Jeff
http://weblogs.sqlteam.com/JeffS

jhermiz

3564 Posts

Posted - 2007-12-18 : 09:36:38

quote:
Originally posted by jsmith8858

just use:

if ViewState("ReferrerURL") Is Nothing Then ....

You cannot apply the ToString() method on a variable that is not set to an object, so if the ViewState("..") return nothing, the call to ToString() will always generate an error.

- Jeff
http://weblogs.sqlteam.com/JeffS

Makes sense thank you

Weblog -- [url]http://weblogs.sqlteam.com/jhermiz[/url]

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