CType not working for Button

[tshad]

I have the following:

sub submitQuestion_ click(Sender as Object, e as EventArgs)
Dim submitButton as Button = CType(sender,Bu tton)

This gives me an error that says:

" System.InvalidC astException: Specified cast is not valid. "

Why is that?

Sender is a button.

Tom

[Mythran]

"tshad" <ts**********@f tsolutions.com> wrote in message
news:OB******** ******@TK2MSFTN GP14.phx.gbl...

I have the following:

sub submitQuestion_ click(Sender as Object, e as EventArgs)
Dim submitButton as Button = CType(sender,Bu tton)

This gives me an error that says:

" System.InvalidC astException: Specified cast is not valid. "

Why is that?

Sender is a button.

Tom

Try this and if you still can't figure it out, post the results...

Sub submitQuestion_ Click(ByVal Sender As Object, ByVal e As EventArgs)
Response.Write( Sender.GetType( ).ToString())
End Sub

Then run the application and click the button.

If this doesn't help, remember to post what is printed.

Mythran

[imsinc]

Try this:

Dim submitButton = CType(sender, Button)
Jason Bentley

[tshad]

"Mythran" <ki********@hot mail.comREMOVET RAIL> wrote in message
news:e5******** ******@TK2MSFTN GP14.phx.gbl...

"tshad" <ts**********@f tsolutions.com> wrote in message
news:OB******** ******@TK2MSFTN GP14.phx.gbl...

I have the following:

sub submitQuestion_ click(Sender as Object, e as EventArgs)
Dim submitButton as Button = CType(sender,Bu tton)

This gives me an error that says:

" System.InvalidC astException: Specified cast is not valid. "

Why is that?

Sender is a button.

Tom

Try this and if you still can't figure it out, post the results...

Sub submitQuestion_ Click(ByVal Sender As Object, ByVal e As EventArgs)
Response.Write( Sender.GetType( ).ToString())
End Sub

Then run the application and click the button.

If this doesn't help, remember to post what is printed.

I did that and got the result:

sender type = System.Web.UI.W ebControls.Butt on

Tom
Mythran

[tshad]

<im****@gmail.c om> wrote in message
news:11******** **************@ o13g2000cwo.goo glegroups.com.. .

Try this:

Dim submitButton = CType(sender, Button)
Actually, it seems both ways work.

I don't know why my old line wasn't working. I just copied the line back in
from my original post and it work. Not sure what happened.

You're way works also, BTW.

Why would that work, I thought you had to have the "as" when dimming a
variable?

Thanks,

Tom

Jason Bentley

[imsinc]

Yes, but you are not really creating a new button, you are just copying
an existing button.

Jason Bentley
http://geekswithblogs.net/jbentley

[tshad]

<im****@gmail.c om> wrote in message
news:11******** **************@ o13g2000cwo.goo glegroups.com.. .

Yes, but you are not really creating a new button, you are just copying
an existing button.
But aren't you just making a new instance of that button?

And I thought you always had to give it a type (which is obviously not the
case here as it does work) if you Dimmed it.

Tom
Jason Bentley
http://geekswithblogs.net/jbentley

[imsinc]

I do not think so, you are creating a button that references the
original button which also takes the original button's type.

Jason Bentley
http://geekswithblogs.net/jbentley

[tshad]

<im****@gmail.c om> wrote in message
news:11******** *************@o 13g2000cwo.goog legroups.com...

I do not think so, you are creating a button that references the
original button which also takes the original button's type.
So if I am creating a variable and assigning it a value, does that mean I
don't need to use the "as", such as:

Dim ktr = 135

or

Dim name = "Franklin"

or

Can I change:

Dim oGrid as DataGrid =
CType(DataList1 .Items(DataList 1.SelectedIndex ).FindControl(" DataGrid1"),Dat aGrid)

to

Dim oGrid =
CType(DataList1 .Items(DataList 1.SelectedIndex ).FindControl(" DataGrid1"),Dat aGrid)

Not that I would, just trying to see what you can and cannot do and why.

Thanks,

Tom


Jason Bentley
http://geekswithblogs.net/jbentley

[imsinc]

Tom, I don't see a problem with most of those but your samples above
were not exactly what we were doing before. We were using CType. The
oGrid may be a little different. I don't see any reason why it will not
work if you use Dim oGrid = CType(DataGrid1 , DataGrid). Keep in mind,
though, you are referencing an existing object, not creating a new. C#
is my first language, also, and you should consult a knowledgable
VB.NET person before using it in production.