How can I check whether or not a registry key object is = Nothing?

  • Thread starter Thread starter Christian Blackburn
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C

Christian Blackburn

Hi Gang,
Sometimes when I try to open a registry it doesn't exist and therefore the
object reference is equal to nothing. However VB.NET 2003 doesn't allow the
syntax if
If objReg <> Nothing then
'do this
End if

Can somebody tell me another way to check if the key failed to open? I
realize I can just use error handling, but I prefer to make that the last
resort :).
Cheers,
Christian
 
Christian Blackburn said:
Hi Gang,
Sometimes when I try to open a registry it doesn't exist and therefore the
object reference is equal to nothing. However VB.NET 2003 doesn't allow the
syntax if
If objReg <> Nothing then
'do this
End if
Click to expand...

The operators = and <> are operators that work on objects. But Nothing
isn't an object. It's just a reference. Nothing is a reference that fails
to refer to an object. It is the "null pointer" of VB.

You need the operator for object reference identity: 'is'.

If not objReg is Nothing then
'do this
End if

'is' is an operator that operates on references, not objects. It tells you
whether two references are equal. Two references are equal just in case
they refer to the same object, or both are Nothing.

David
 
Hello,

Christian Blackburn said:
Sometimes when I try to open a registry it doesn't exist
and therefore the object reference is equal to nothing. However
VB.NET 2003 doesn't allow the syntax if
If objReg <> Nothing then
'do this
End if
Click to expand...

\\\
If Not objReg Is Nothing Then
...
End If
///
 
Thank you very much David and Herfried,
I'm sure I'll use what I just learned trillion times over :).
Cheers,
Christian
 
Hello,

Christian Blackburn said:
Thank you very much David and Herfried,
I'm sure I'll use what I just learned trillion times over :).
Click to expand...

In addition to my previous post:

MSDN says that 'OpenSubKey' returns 'Nothing' if the key doesn't exist.
 
Hi Herfried,
That is exactly what I said :).
In addition to my previous post:

MSDN says that 'OpenSubKey' returns 'Nothing' if the key doesn't exist.
Sometimes when I try to open a registry [key and] it doesn't exist and therefore the
object reference is equal to nothing.
Click to expand...
Click to expand...

Thanks so much for all the help Herfried you rate, I even added you to spell
check :).
Cheers,
Christian Blackburn
 
Hi Herfried

|| Herfried, I even added you to spell check :).

What better compliment?! ;-)

Regards,
Fergus
MVP [Windows Keyboard, PC Power Switch]
 
Hi Herfried,
It's just that Outlook Express doesn't recognize your name as a word. It's
no big deal it's just, because it's a foreign name. What I'm trying to say
is that I've had to write you thank you so many times that it was worth my
time to add you to spell check. What I'm trying to say with a little bit of
comedy is that you help me a lot and I appreciate it :).
Cheers,
Christian Blackburn
 
Hi Herfried, Christian,

Lol, and I was just giving it a bit of emphasis. ;-)

Regards,
Fergus
 
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