Jawad Khan

# re: How to validate a valid GUID Value in C#

Thank you very much for sharing your code. It has been a great help.

# re: How to validate a valid GUID Value in C#

Microsoft's Regex stuff is really poorly documented, it seems. Thanks for this.

# re: How to validate a valid GUID Value in C#

Thanks for the great code!

# re: How to validate a valid GUID Value in C#

Thanks! This helped me. Not sure why they don't have a TryParse for Guids.

# re: How to validate a valid GUID Value in C#

Thank you so much. Exactly what I'm looking for

# re: How to validate a valid GUID Value in C#

fix the code for this kind of input
"{e73a048d- bf27-4f12-9731-8b2076e8891f"

# re: How to validate a valid GUID Value in C#

sry there was an extra space after the 1st dash in my earlier post -->

fix the code for this kind of input
"{e73a048d- bf27-4f12-9731-8b2076e8891f"

its should be
"{e73a048d-bf27-4f12-9731-8b2076e8891f"

# re: How to validate a valid GUID Value in C#

Why the hell my comment had a swastika icon next to it???

# re: How to validate a valid GUID Value in C#

It's probably an auto-generated ip address to icon. Every ip has his unique icon.

Funny though

>Why the hell my comment had a swastika icon next to it???

# re: How to validate a valid GUID Value in C#

My thanks also for this code. I wonder what my graphic will look like?

# re: How to validate a valid GUID Value in C#

Thanks for the code

# re: How to validate a valid GUID Value in C#

Good stuff, thanks!

# re: How to validate a valid GUID Value in C#

Thank you so much,
There is another silliy solution without RegEx for that.

public static bool IsGuid(string guidString)
{
bool bResult=false;
try
{
Guid g = new Guid(guidString);
bResult=true;
}
catch
{
bResult=false;
}

return bResult;
}

If the guidString is not valid, Guid class throws an error.

# re: How to validate a valid GUID Value in C#

askl;ja awerj pojasdf kl;jaeiopuawr[iuoaer'kl asf'klasdfopw]tiotklj a;lksfa wpoeir adjklj;poiqwer

# re: How to validate a valid GUID Value in C#

cool. I want i dyn image too :)

# re: How to validate a valid GUID Value in C#

This is great though it is doing two things 1. Validating 2. Converting string to Guid. I would rather do just the check which removes the coupling:

private static readonly Regex guidPattern = new Regex(@"^(\{){0,1}[0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12}(\}){0,1}$", RegexOptions.Compiled);

public static bool IsGuid(this string input)
{
return guidPattern.IsMatch(input);
}

then create the guid instance as needed, SRP and all that.

# re: How to validate a valid GUID Value in C#

Very nice, thanks for posting.

# re: How to validate a valid GUID Value in C#

This code has a bug, allowing unmatched curly braces.

You can pass in a string like:

{1102F615-9508-41EF-9699-B517C09D5FEE

and the method will return true.

# re: How to validate a valid GUID Value in C#

Further to my comment, you could change the regex to enforce the use of curly braces. Or change it not to have curly braces at all. You could pass in an extra parameter to the method to to switch between "must have both braces" or "must not have any braces".

# re: How to validate a valid GUID Value in C#

I have a question and I know this is an OLD thread. However, if you have a variable that is already of type guid, your regex does not verify it is not an empty guid. An empty guid is also a properly formatted guid.

Do you have a regex that matches a valid guid that isn't an empty guid? I have modified one to find an empty guid, but I cannot seem to invert it.


Thank you

# re: How to validate a valid GUID Value in C#

Thanx dude, you save me from so much work trying to figure this out myself!

# re: How to validate a valid GUID Value in C#

I wanna know how to create a GUID :-((((

# re: How to validate a valid GUID Value in C#

Excellent! I can't believe they left this out

# re: How to validate a valid GUID Value in C#

to validate an empty guid just check for guid.empty.

# re: How to validate a valid GUID Value in C#

//Well, This is how you generate a new Guid:
Guid mynewguid = Guid.NewGuid();

I think the try-catch method is better, because there are various valid Guid string formats, see: <quote>A String that contains a GUID in one of the following formats ('d' represents a hexadecimal digit whose case is ignored): 32 contiguous digits: dddddddddddddddddddddddddddddddd -or- Groups of 8, 4, 4, 4, and 12 digits with hyphens between the groups. The entire GUID can optionally be enclosed in matching braces or parentheses: dddddddd-dddd-dddd-dddd-dddddddddddd -or- {dddddddd-dddd-dddd-dddd-dddddddddddd} -or- (dddddddd-dddd-dddd-dddd-dddddddddddd) -or- Groups of 8, 4, and 4 digits, and a subset of eight groups of 2 digits, with each group prefixed by "0x" or "0X", and separated by commas. The entire GUID, as well as the subset, is enclosed in matching braces: {0xdddddddd, 0xdddd, 0xdddd,{0xdd,0xdd,0xdd,0xdd,0xdd,0xdd,0xdd,0xdd}} All braces, commas, and "0x" prefixes are required. All embedded spaces are ignored. All leading zeroes in a group are ignored.The digits shown in a group are the maximum number of meaningful digits that can appear in that group. You can specify from 1 to the number of digits shown for a group. The specified digits are assumed to be the low order digits of the group. </quote>

When you look at the Guid constructer code it doesn't use regex. The correct regex would have to match all valid guid formats or at least not match any bad guids

Also when catching the exception it is best to also catch OverflowException (as well as FormatException).