I have a form who's height I would like to change in code. I would have
supposed something like the following would work but it does not:

Me.Size.Height = 292

I get "Expression is a value and therefore can not be the target of an
asignment"

What am I missing?

"Woody Splawn" <(E-Mail Removed)> scripsit:
> I have a form who's height I would like to change in code. I would have
> supposed something like the following would work but it does not:
>
> Me.Size.Height = 292
>
> I get "Expression is a value and therefore can not be the target of an
> asignment"

Use 'Me.Height = 292' instead.

--
Herfried K. Wagner
MVP · VB Classic, VB.NET
<http://www.mvps.org/dotnet>

Size is a class, not a simple structure. Try one of the following:

Me.Height = 292
or
Me.Size = new Size(Me.Size.Width, 292)


-----
Rafael Pivato


"Woody Splawn" <(E-Mail Removed)> escreveu na mensagem
news:(E-Mail Removed)...
> I have a form who's height I would like to change in code. I would have
> supposed something like the following would work but it does not:
>
> Me.Size.Height = 292
>
> I get "Expression is a value and therefore can not be the target of an
> asignment"
>
> What am I missing?
>
>
>

Hi Woody,

The documentation for Size says that you can get or set the Width and
Height, which is entirely reasonable. What it doesn't say is that you <can't>
when it's the Size of a Control!! The bit you're missing is informative
documentation!!

You can create a new Size and assign it in one go.
Me.Size = New Size (Me.Size.Width, 292)

But it's easier to say Huh! to the Size and just go for the Height

Me.Height = 292. ;-))

Regards,
Fergus.

Hi Rafael,

Size <is> a structure, but its fields are read-only in Controls, for some
reason.

Regards,
Fergus

"Fergus Cooney" <filter-(E-Mail Removed)> schrieb
>
> Size <is> a structure, but its fields are read-only in Controls,
> for some reason.

Really? I think, the thing is that retrieving the Size returns a copy of the
Size (because it is a value type), and changing the property of the copy
doesn't make sense.


--
Armin

Fergus,

Fundamentally it is a class for sure. The question that, maybe, you are
trying to rise is that this class inherits System.ValueType, but that is a
long question.. They are not Pascal-like (VB6-like) structures.



And more. Size.Width and Size.Height are not read-only properties from Size.

The problem was that Woody was trying to access indirectly the Form.Size. It
can't.

Look at this code. It will work too:



Dim MySize as Size

MySize = Me.Size ' value assignment

MySize.Width = 294

Me.Size = MySize ' value assignment again





The indirect assignment uses a "temporary allocation" that will raise the
error:



Me.Size.Width = 294





Look at this topic from MSDN: "Expression is a value and therefore cannot be
the target of an assignment" from Visual Basic Reference Error Messages.





-------------------------------

Rafael Pivato



"Fergus Cooney" <filter-(E-Mail Removed)> escreveu na mensagem
news:(E-Mail Removed)...
> Hi Rafael,
>
> Size <is> a structure, but its fields are read-only in Controls, for
some
> reason.
>
> Regards,
> Fergus
>
>

:-) nice and clean.... :-)

"Armin Zingler" <(E-Mail Removed)> escreveu na mensagem
news:%(E-Mail Removed)...
> "Fergus Cooney" <filter-(E-Mail Removed)> schrieb
> >
> > Size <is> a structure, but its fields are read-only in Controls,
> > for some reason.
>
> Really? I think, the thing is that retrieving the Size returns a copy of
the
> Size (because it is a value type), and changing the property of the copy
> doesn't make sense.
>
>
> --
> Armin
>

Hi Rafael,

|| Fundamentally it [Size] is a class for sure.

For me a ValueType is not a class in the sense that it
is an embedded structure and a containing object has
(needs) no object reference to access it. No object.
No independant existance. To me it is not a class but
it is class-like in that it inherits from System.Object
and System.ValueType.

I imagine your definition of 'fundamentally' discounts the
above definition.

For me the lack of independent existence and object
reference are fundamental.


|| Size.Width and Size.Height are not read-only properties of Size.

True. Lol, it would be strange if they were.
I said that <in Controls> they are read-only.

|| Look at this topic from MSDN: "Expression is a
|| value and therefore cannot be the target of an
|| assignment" from Visual Basic Reference Error Messages.

The topic says
|| An expression occurs in a context that assigns a value to it.
|| Only writeable variables, properties, and array elements
|| can have values assigned to them during execution.

I'm not sure why you want me to read it. It says exactly what
I said but in more words - Size.Width and Size.Height are
read-only in [the context of] Controls.

|| The problem was that Woody was trying to access indirectly
|| the Form.Size. It can't.

I was aware of both those facts. Here's my challenge - and the
only bit of this that matters -

Can you say why? ;-)

Regards,
Fergus

Hi Armin,

Doh! ;-)

Regards,
Fergus