Is there a GUID.TryParse() in .NET 3.5?

Question

UPDATE

Guid.TryParse is available in .NET 4.0

END UPDATE

Obviously there is no public GUID.TryParse() in .NET CLR

Answer 1

In terms of why there isn't one, it's an oversight. There will be a Guid.TryParse in .NET 4 (see BCL blog post for details).

Answer 2

This should work:

@"^\{?[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}\}?$"

Answer 3

This implementation of a TryParse for Guids uses a try-catch in order to catch missformed Guids. It is implemented as extension method und must be placed in a static class:

public static bool TryParseGuid(this string s, out Guid guid)
{
    try {
        guid = new Guid(s);
        return true;
    } catch {
        guid = Guid.Empty;
        return false;
    }
}

It can be called with

string s = "{CA761232-ED42-11CE-BACD-00AA0057B223}";
Guid id;
if (s.TryParseGuid(out id) {
    // TODO: use id
} else {
    // Sorry not a valid Guid.
}

---

Starting with C# 7.0 / Visual Studio 2017, you can call it with:

string s = "{CA761232-ED42-11CE-BACD-00AA0057B223}";
if (s.TryParseGuid(out Guid id) {
    // TODO: use id
} else {
    // Sorry not a valid Guid.
}

---

UPDATE

Since Visual Studio 2010 / .NET Framework 4.0, System.Guid provides a TryParse and a TryPareExact method.

Answer 4

There's no TryParse functionality in the .NET Framework to my knowledge at this moment. You'll have to resort to RegEx or the try-catch option. RegEx isn't my cup of tea, so I'm sure someone else will post an answer.

Exceptions are expensive performance wise, so my vote goes to the RegEx option.

Answer 5

Guid.TryParse implementation using regular expressions.

Answer 6

IsGuid implemented as extension method for string...

public static bool IsGuid(this string stringValue)
{
   string guidPattern = @"[a-fA-F0-9]{8}(\-[a-fA-F0-9]{4}){3}\-[a-fA-F0-9]{12}";
   if(string.IsNullOrEmpty(stringValue))
     return false;
   Regex guidRegEx = new Regex(guidPattern);
   return guidRegEx.IsMatch(stringValue);
}