basic regex question

[Jeff]

....hoping someone can help someone still new to vb.net 2005 with something
new to him.

....been successfully using the regular expression validators from the
toolbox, but now I have need to do something strictly with code.

....need to determine if a stored string matches a stored regular expression.

....not sure what to search under for an example to give me a starting point.
I can figure out the actual expression syntax and the rest if someone can
get me started.

e.g., something along these lines

dim myregex as new regex
if mystoredstring = regex then
DoAllKindsOfStuff()
end if

Thanks

jeff

 

[Andrew Morton]

...hoping someone can help someone still new to vb.net 2005 with
something new to him.

...been successfully using the regular expression validators from the
toolbox, but now I have need to do something strictly with code.

...need to determine if a stored string matches a stored regular
expression.

I think you're looking for the RegEx.IsMatch method.

Andrew

 

[rowe_newsgroups]

...hoping someone can help someone still new to vb.net 2005 with something
new to him.

...been successfully using the regular expression validators from the
toolbox, but now I have need to do something strictly with code.

...need to determine if a stored string matches a stored regular expression.

...not sure what to search under for an example to give me a starting point.
I can figure out the actual expression syntax and the rest if someone can
get me started.

e.g., something along these lines

dim myregex as new regex
if mystoredstring = regex then
DoAllKindsOfStuff()
end if

Thanks

jeff

Off the top of my head:

Imports System.Text.RegularExpressions

If Regex.IsMatch(mystoredstring, myregexpattern) Then
DoAllKindsOfStuff()
end if

Thanks,

Seth Rowe

 

[Jeff]

Okay, now I'm really confused.

I got this figured out somewhat, but either there is a major bug somewhere,
or I don't understand something fundamental (and it is likely the latter)

If I uses a regular expression validator from the toolbox and the expression
[a-zA-Z1-9]* it will properly match letters and numbers.

The exact same regular expression in the code below fails and matches
everything. Something seems to be going on everytime that I enter a reg
expression with a bracket - it will work with the toolbox validator, but not
when I use all vb code.

Can someone explain? I'm lost.

Dim regexobj As Regex = New Regex("[a-zA-Z1-9]*")

If RegexObj.IsMatch(TBUser.Text) = False Then

 

[rowe_newsgroups]

Okay, now I'm really confused.

I got this figured out somewhat, but either there is a major bug somewhere,
or I don't understand something fundamental (and it is likely the latter)

If I uses a regular expression validator from the toolbox and the expression
[a-zA-Z1-9]* it will properly match letters and numbers.

The exact same regular expression in the code below fails and matches
everything. Something seems to be going on everytime that I enter a reg
expression with a bracket - it will work with the toolbox validator, but not
when I use all vb code.

Can someone explain? I'm lost.

Dim regexobj As Regex = New Regex("[a-zA-Z1-9]*")

If RegexObj.IsMatch(TBUser.Text) = False Then

I'm just guessing - but it may have to do with the RegexOptions you
are using - try experimenting with them and see if it makes a
difference.

Also, you might want to post some sample text and the complete regex
pattern that is causing the problem - that way I can take a better
look at it.

Thanks,

Seth Rowe

 

[Jeff]

I'm just guessing - but it may have to do with the RegexOptions you
are using - try experimenting with them and see if it makes a
difference.

Also, you might want to post some sample text and the complete regex
pattern that is causing the problem - that way I can take a better
look at it.

Thanks,

Seth Rowe

Okay, I think that I have much of this figured out. The validator through
the toolbox (is there a good way to say this?) does not evaluate empty
textbox values regardless of the regex expression, while the hardcoded
version works essentially like all of the instructions that I see about
using regex. I didn't pick up on that initially, and that was causing the
confusion.

I think that I have it going now.

Thanks for the help.