GetType() question

[h]

Hi!

I have a user control called ListItemControl . This works ok:

ListItemControl li = new ListItemControl ();

When I iterate with Enumerator through all controls using:

IEnumerator e = pnlList.Control s.GetEnumerator ();
while (e.MoveNext())
{
object o = e.Current;
if(o.GetType(). Equals(GetType( ListItemControl )))
{
i++;
}
}

I get 'ListItemContro lTest.ListItemC ontrol' denotes a 'class' where
a 'variable' was expected
What do I do wrong? I looked at the MSDN sample and it looked pretty
straight forward, but I can't get it to work.

thanks,
h

[Justin Rogers]

You should be using typeof() instead of GetType() or just use the is keyword.

if ( o is ListItemControl ) {
}
--
Justin Rogers
DigiTec Web Consultants, LLC.
Blog: http://weblogs.asp.net/justin_rogers

"h" <[e-mail] > wrote in message
news:6r******** *************** *********@4ax.c om...

Hi!

I have a user control called ListItemControl . This works ok:

ListItemControl li = new ListItemControl ();

When I iterate with Enumerator through all controls using:

IEnumerator e = pnlList.Control s.GetEnumerator ();
while (e.MoveNext())
{
object o = e.Current;
if(o.GetType(). Equals(GetType( ListItemControl )))
{
i++;
}
}

I get 'ListItemContro lTest.ListItemC ontrol' denotes a 'class' where
a 'variable' was expected
What do I do wrong? I looked at the MSDN sample and it looked pretty
straight forward, but I can't get it to work.

thanks,
h

[J.Marsch]

You use GetType() to get the type from an object instance. To get a type
from a classname, use typeof():
so, instead of:

if(o.GetType(). Equals(GetType( ListItemControl ))) use
if(o.GetType(). Equals(typeof(L istItemControl) ))
// word of caution: I haven't tried to compile your code, but I think this
should solve that problem.

Oh, I'm curious: Why did you explicitly retrieve the enumerator instead of
just using a foreach() loop?
"h" <[e-mail] > wrote in message
news:6r******** *************** *********@4ax.c om... Hi!

I have a user control called ListItemControl . This works ok:

ListItemControl li = new ListItemControl ();

When I iterate with Enumerator through all controls using:

IEnumerator e = pnlList.Control s.GetEnumerator ();
while (e.MoveNext())
{
object o = e.Current;
if(o.GetType(). Equals(GetType( ListItemControl )))
{
i++;
}
}

I get 'ListItemContro lTest.ListItemC ontrol' denotes a 'class' where
a 'variable' was expected
What do I do wrong? I looked at the MSDN sample and it looked pretty
straight forward, but I can't get it to work.

thanks,
h

[Rakesh Rajan]

Hi,

Use the if statement this way:
if( o is ListItemControl )
....

--
Rakesh Rajan
"h" wrote:

Hi!

I have a user control called ListItemControl . This works ok:

ListItemControl li = new ListItemControl ();

When I iterate with Enumerator through all controls using:

IEnumerator e = pnlList.Control s.GetEnumerator ();
while (e.MoveNext())
{
object o = e.Current;
if(o.GetType(). Equals(GetType( ListItemControl )))
{
i++;
}
}

I get 'ListItemContro lTest.ListItemC ontrol' denotes a 'class' where
a 'variable' was expected
What do I do wrong? I looked at the MSDN sample and it looked pretty
straight forward, but I can't get it to work.

thanks,
h

[PseudoBill]

GetType() vs typeof(): Microsoft should have been more careful with
cross-language confusion between VB and C#.

Check
http://www.tangiblesoftwaresolutions...rsion_Tips.htm
for an interesting summary of this issue and a couple of others.
Posted Via Usenet.com Premium Usenet Newsgroup Services
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[h]

On Fri, 11 Jun 2004 10:54:18 -0500, "J.Marsch"
<je****@ctcdeve loper.com> wrote:

Oh, I'm curious: Why did you explicitly retrieve the enumerator instead of
just using a foreach() loop?

I'm still getting used to C# (late transition from VB which I have
used for quite a while). I was looking for "better" or other way to do
this.

Can you give advice if this is preferable way or not?

thanks everyone for your replies!

h

[J.Marsch]

The only reason that I asked is that the enumerator is usually something
that you don't touch directly. Instead, if the object that you want to loop
through supports IEnumerable, you generally use a foreach loop (which uses
the enumerator under the covers for your). The foreach lets you declare a
variable for the member type of the collection you are enumerating. The form
looks like this:

foreach(MemberT ype memberVar in CollectionToBeE numerated)
{
}

Basically, this uses the enumerator to loop through every member in the
collection. Each member is cast as MemberType and assigned to memberVar.

So, you could rewrite your code something like this (haven't tried
compiling, might need some tweaking):

foreach(Control aControl in pnlList.Control s)
{
if(aControl is ListItemControl )
i++;
}

NOTE: I am using Control because I know that all of the members of Controls
inherit from control. If I use a type that is too restrictive I will get
invalid cast errors. So, if I used TextBox, and there was a button in the
Controls collection, I would get an invalid cast exception when I hit the
button.

"h" <[e-mail] > wrote in message
news:h5******** *************** *********@4ax.c om...

On Fri, 11 Jun 2004 10:54:18 -0500, "J.Marsch"
<je****@ctcdeve loper.com> wrote:

Oh, I'm curious: Why did you explicitly retrieve the enumerator instead ofjust using a foreach() loop?

I'm still getting used to C# (late transition from VB which I have
used for quite a while). I was looking for "better" or other way to do
this.

Can you give advice if this is preferable way or not?

thanks everyone for your replies!

h