how to check for numeric and enter in text box

[anthonymelillo]

Is there any way to check the entry in a text box and make sure it is
numeric ?

Also, can I catch the enter key and make it call a button click event ?

Sorry if this sounds stupid, but I am trying to come to grips with the
differences in .Net since all my prior programming was done in VB6

Thanks
--
Tony

[Armin Zingler]

"anthonymelillo " <no************ @earthlink.net> schrieb

Is there any way to check the entry in a text box and make sure it
is numeric ?

Also, can I catch the enter key and make it call a button click event
?
Have a look at the Defaultbutton property of the Form.
Sorry if this sounds stupid, but I am trying to come to grips with
the differences in .Net since all my prior programming was done in
VB6

I prefer not to limit the user's input when typing. Try to convert the
Textbox' content to a numeric value using the (shared) Parse function of the
destination type. Catch occuring exceptions to find out if conversion was
successful.
--
Armin

[Herfried K. Wagner [MVP]]

"anthonymelillo " <no************ @earthlink.net> scripsit:

Is there any way to check the entry in a text box and make sure it is
numeric ?
You can use 'Double.TryPars e' or 'IsNumeric'.
Also, can I catch the enter key and make it call a button click event ?

Create a button and assign it to the form's 'AcceptButton' property.

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

[Stephen]

try the IdNumeric() function....
if IsNumeric then
do something cool
else
messageBox("So non-cool error")
end if

hope it helps
"Armin Zingler" <az*******@free net.de> wrote in message
news:el******** ******@tk2msftn gp13.phx.gbl...

"anthonymelillo " <no************ @earthlink.net> schrieb

Is there any way to check the entry in a text box and make sure it
is numeric ?

Also, can I catch the enter key and make it call a button click event
?
Have a look at the Defaultbutton property of the Form.

Sorry if this sounds stupid, but I am trying to come to grips with
the differences in .Net since all my prior programming was done in
VB6

I prefer not to limit the user's input when typing. Try to convert the
Textbox' content to a numeric value using the (shared) Parse function of

the destination type. Catch occuring exceptions to find out if conversion was
successful.
--
Armin

[Armin Zingler]

"Stephen" <St*****@johnst ontrading.com> schrieb

try the IdNumeric() function....
if IsNumeric then
do something cool
else
messageBox("So non-cool error")
end if

I think, IsNumeric does not accept exactly the same formats as the Parse
method of the types does. It also can not check if it is within the value
range of the destination data type.
--
Armin

[Cor]

Armin,
Seriously I d'not understand this answer, (I hope you are not talking about
dragged information to the textbox).

I think, IsNumeric does not accept exactly the same formats as the Parse
method of the types does. It also can not check if it is within the value
range of the destination data type.

In a textbox is normaly only text, so what is wrong to ask in a button event
"if not isnumeric(textb ox1.text)".
I am really curious (for a simple method, not the best maybe)?

And for the not simple method I am as well as intrested?
:-) just to say that is well ment.
Cor

[Armin Zingler]

"Cor" <no*@non.com> schrieb

Armin,
Seriously I d'not understand this answer, (I hope you are not talking
about dragged information to the textbox).

I think, IsNumeric does not accept exactly the same formats as the
Parse method of the types does. It also can not check if it is
within the value
range of the destination data type.

In a textbox is normaly only text, so what is wrong to ask in a
button event "if not isnumeric(textb ox1.text)".
I am really curious (for a simple method, not the best maybe)?

And for the not simple method I am as well as intrested?
:-) just to say that is well ment.
Cor

Dim i As Integer
Dim s As String = "1234567890 .12"
If IsNumeric(s) Then
i = Integer.Parse(s )
End If

Means: Calling IsNumeric doesn't help to find out whether the string can be
converted. The only way to find it out is trying to convert it (or call
Double.TryParse as Herfried mentioned).

--
Armin

[Armin Zingler]

"Cor" <no*@non.com> schrieb

Armin,
Seriously I d'not understand this answer, (I hope you are not talking
about dragged information to the textbox).

I think, IsNumeric does not accept exactly the same formats as the
Parse method of the types does. It also can not check if it is
within the value
range of the destination data type.

In a textbox is normaly only text, so what is wrong to ask in a
button event "if not isnumeric(textb ox1.text)".
I am really curious (for a simple method, not the best maybe)?

And for the not simple method I am as well as intrested?
:-) just to say that is well ment.
Cor

....and what I was trying to say in my first post: ;-)
Usually you also need to convert the string to a numeric data type (not only
check if it is numeric). I am not 100% sure, but I think that IsNumeric does
not perform exactly the same check as the conversion function called later.
Therfore IsNumeric does not help here.
--
Armin

[Cor]

Armin,
I try it and what the culture does with it, I give you an anser then.
Take some time (I have no time for that, but when it is longer then 3 days
it is never :-)
But I am intrested so I think it will be tomorrow.

Thanks,
Cor

[Herfried K. Wagner [MVP]]

"Armin Zingler" <az*******@free net.de> scripsit:

try the IdNumeric() function....
if IsNumeric then
do something cool
else
messageBox("So non-cool error")
end if

I think, IsNumeric does not accept exactly the same formats as the Parse
method of the types does. It also can not check if it is within the value
range of the destination data type.

This depends on the data type of the destination variable.

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