General Development

Simple code to detect letters in VB.net? – DeathFox

DeathFox
Member

Posts: 57
From:
Registered: 04-25-2006
 		How do I make it so that a textbox just accepts integers? And I dont wanna use a masked textbox, just a normal textbox
bennythebear

Member

Posts: 1225
From: kentucky,usa
Registered: 12-13-2003
 		in the textchanged event of the textbox you could put in some code to check to see if a letter or "." has been entered, and if so pop up an error message. i'm not really sure if that's what you're looking for, but there's prob'ly a better answer anyway, that's just a suggestion.

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DeathFox
Member

Posts: 57
From:
Registered: 04-25-2006
 		But that method is too long, I need to compare all 24 letters if they exist on a textbox
Tonnyx

Member

Posts: 140
From: Indiana, USA
Registered: 08-02-2005
 		Can you use RegEx (regular expressions)?

I did a google search, which yielded this: http://visualbasic.about.com/od/usingvbnet/l/blregexa.htm (see the bottom of the page).

I'm sure there are probably better resources online, but I actually don't know any regex myself. I've just been around Clint enough to know what it does, and that it's very powerful.

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it's pronounced "tonics"
bwoogie

Member

Posts: 380
From: kansas usa
Registered: 03-12-2005
quote:
Originally posted by DeathFox:
But that method is too long, I need to compare all 24 letters if they exist on a textbox

umm, dont you mean 26 letters? :|

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~~~boogie woogie woogie~~~
samw3

Member

Posts: 542
From: Toccoa, GA, USA
Registered: 08-15-2006
 		I'm not sure how to do exactly it in VB, but the algorithm I would use would be in the key press event. Here is some pseudo-code:

validChars = "0123456789"
if InStr(validChars, keyPressed) <> 0 then
' Add the char to the text box
end if
' Otherwise just skip it.

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Sam Washburn
Calin

Member

Posts: 358
From: Moldova
Registered: 12-04-2006
 		As everyone else I don't know how the code would look in VB but you can try to convert the text in the textbox to an integer (in case that helps in C# that's Convert.ToInt32("string")). If the conversion fails the input string in not a valid number. That's how use to do it although there might be better way of solving the problem.
DeathFox
Member

Posts: 57
From:
Registered: 04-25-2006
 		But the program crasses when I do it, How can I detect if it failed?