Help with InvalidCastException

[=?Utf-8?B?Q2hyaXM=?=]

Hi,
I have a problem with part of my code. I am trying to Cache a Generic
Collection

Private nodeCollection As New Generic.List(Of MenuNode)

If (Cache("MainMen u")) = Nothing Then
...
nodeCollection = menudal.FetchMe nu()
Cache.Insert("M ainMenu", nodeCollection)
End If

Then I read from Cache to populate my menu. When I run the project though, I
get

"InvalidCastExc eption"
Operator '=' is not defined for type 'List(Of MenuNode)' and 'Nothing'.

at the line If (Cache("MainMen u")) = Nothing Then

Any ideas?

[Dave Sexton]

Re: Help with InvalidCastExce ption

Hi,

It's been a while since I did VB but I think you have to use "Is Nothing"
not "= Nothing" for a comparison.

--
Dave Sexton

http://davesexton.com/blog

"Chris" <Chris@discussi ons.microsoft.c omwrote in message
news:70DB84E1-E082-421D-9765-6535C689675E@mi crosoft.com...

Hi,
I have a problem with part of my code. I am trying to Cache a Generic
Collection
>
Private nodeCollection As New Generic.List(Of MenuNode)
>
If (Cache("MainMen u")) = Nothing Then
...
nodeCollection = menudal.FetchMe nu()
Cache.Insert("M ainMenu", nodeCollection)
End If
>
Then I read from Cache to populate my menu. When I run the project though,
I
get
>
"InvalidCastExc eption"
Operator '=' is not defined for type 'List(Of MenuNode)' and 'Nothing'.
>
at the line If (Cache("MainMen u")) = Nothing Then
>
Any ideas?
>

[RobinS]

Re: Help with InvalidCastExce ption

You're correct. Or you can check "IsNot Nothing" if you're feeling
contrary.

Robin S.
---------------------
"Dave Sexton" <dave@jwa[remove.this]online.comwrote in message
news:%23PkNA6gK HHA.1252@TK2MSF TNGP02.phx.gbl. ..

Hi,
>
It's been a while since I did VB but I think you have to use "Is
Nothing" not "= Nothing" for a comparison.
>
--
Dave Sexton

http://davesexton.com/blog

>
"Chris" <Chris@discussi ons.microsoft.c omwrote in message
news:70DB84E1-E082-421D-9765-6535C689675E@mi crosoft.com...

>Hi,
>I have a problem with part of my code. I am trying to Cache a Generic
>Collection
>>
>Private nodeCollection As New Generic.List(Of MenuNode)
>>
>If (Cache("MainMen u")) = Nothing Then
> ...
> nodeCollection = menudal.FetchMe nu()
> Cache.Insert("M ainMenu", nodeCollection)
>End If
>>
>Then I read from Cache to populate my menu. When I run the project
>though, I
>get
>>
>"InvalidCastEx ception"
>Operator '=' is not defined for type 'List(Of MenuNode)' and
>'Nothing'.
>>
>at the line If (Cache("MainMen u")) = Nothing Then
>>
>Any ideas?
>>

>
>