How to validate Guid in .net

Question

Please tell me how to validate GUID in .net and it is unique for always?

Answer 1

2^128 is a very, very large number. It is a billion times larger than the number of picoseconds in the life of the universe. Too large by a long shot to ever validate, the answer is doomed to be "42". Which is the point of using them: you don't have to. If you worry about getting duplicates then you worry for the wrong reason. The odds your machine will be destroyed by a meteor impact are considerably larger.

Duck!

Answer 2

Guid's are unique 99.99999999999999999999999999999999% of the time.

It depends on what you mean by validate?

Code to determine that a Guid string is in fact a Guid, is as follows:

private static Regex isGuid = 
      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);

internal static bool IsGuid(string candidate, out Guid output)
{
    bool isValid = false;
    output = Guid.Empty;

    if(candidate != null)
    {

        if (isGuid.IsMatch(candidate))
        {
            output=new Guid(candidate);
            isValid = true;
        }
    }

    return isValid;
}