Guid.TryParse by Erik Porter

// i think it is easier the following way: (just the bare minimum, build your specific needs around it...)

try {
gcnew Guid(newGuidString);
}
catch (Exception^ e) {
return false;
}
return true;

/// <summary>
/// Converts the string representation of a Guid to its Guid
/// equivalent. A return value indicates whether the operation
/// succeeded.
/// </summary>
/// <param name="s">A string containing a Guid to convert.</param>
/// <param name="result">
/// When this method returns, contains the Guid value equivalent to
/// the Guid contained in <paramref name="s"/>, if the conversion
/// succeeded, or <see cref="Guid.Empty"/> if the conversion failed.
/// The conversion fails if the <paramref name="s"/> parameter is a
/// <see langword="null" /> reference (<see langword="Nothing" /> in
/// Visual Basic), or is not of the correct format.
/// </param>
/// <value>
/// <see langword="true" /> if <paramref name="s"/> was converted
/// successfully; otherwise, <see langword="false" />.
/// </value>
/// <exception cref="ArgumentNullException">
///        Thrown if <pararef name="s"/> is <see langword="null"/>.
/// </exception>
public static bool GuidTryParse(string s, out Guid result)
{
    if (s == null)
        throw new ArgumentNullException("s");

    Regex format = new Regex(
        "^[A-Fa-f0-9]{32}$|" +
        "^({|\\()?[A-Fa-f0-9]{8}-([A-Fa-f0-9]{4}-){3}[A-Fa-f0-9]{12}(}|\\))?$|" +
        "^({)?[0xA-Fa-f0-9]{3,10}(, {0,1}[0xA-Fa-f0-9]{3,6}){2}, {0,1}({)([0xA-Fa-f0-9]{3,4}, {0,1}){7}[0xA-Fa-f0-9]{3,4}(}})$");
    Match match = format.Match(s);

    if (match.Success)
    {
        result = new Guid(s);
        return true;
    }
    else
    {
        result = Guid.Empty;
        return false;
    }
}

---

Test values:

Guid Result, ResultValue;
bool IsValid = false;

// dddddddddddddddddddddddddddddddd
IsValid = ArgumentValidation.GuidTryParse("ca761232ed4211cebacd00aa0057b223", out Result);
Assert.IsTrue(IsValid);
ResultValue = new Guid("ca761232ed4211cebacd00aa0057b223");
Assert.AreEqual<Guid>(Result, ResultValue);

// dddddddd-dddd-dddd-dddd-dddddddddddd
IsValid = ArgumentValidation.GuidTryParse("CA761232-ED42-11CE-BACD-00AA0057B223", out Result);
Assert.IsTrue(IsValid);
ResultValue = new Guid("CA761232-ED42-11CE-BACD-00AA0057B223");
Assert.AreEqual<Guid>(Result, ResultValue);

// {dddddddd-dddd-dddd-dddd-dddddddddddd}
IsValid = ArgumentValidation.GuidTryParse("{CA761232-ED42-11CE-BACD-00AA0057B223}", out Result);
Assert.IsTrue(IsValid);
ResultValue = new Guid("{CA761232-ED42-11CE-BACD-00AA0057B223}");
Assert.AreEqual<Guid>(Result, ResultValue);

// (dddddddd-dddd-dddd-dddd-dddddddddddd)
IsValid = ArgumentValidation.GuidTryParse("(CA761232-ED42-11CE-BACD-00AA0057B223)", out Result);
Assert.IsTrue(IsValid);
ResultValue = new Guid("(CA761232-ED42-11CE-BACD-00AA0057B223)");
Assert.AreEqual<Guid>(Result, ResultValue);

// {0xdddddddd, 0xdddd, 0xdddd,{0xdd,0xdd,0xdd,0xdd,0xdd,0xdd,0xdd,0xdd}}
IsValid = ArgumentValidation.GuidTryParse("{0xCA761232, 0xED42, 0x11CE, {0xBA, 0xCD, 0x00, 0xAA, 0x00, 0x57, 0xB2, 0x23}}", out Result);
Assert.IsTrue(IsValid);
ResultValue = new Guid("{0xCA761232, 0xED42, 0x11CE, {0xBA, 0xCD, 0x00, 0xAA, 0x00, 0x57, 0xB2, 0x23}}");
Assert.AreEqual<Guid>(Result, ResultValue);

IsValid = ArgumentValidation.GuidTryParse("{0xA,0xA,0xA,{0xA,0xA,0xA,0xA,0xA,0xA,0xA,0xA}}", out Result);
Assert.IsTrue(IsValid);
ResultValue = new Guid("{0xA,0xA,0xA,{0xA,0xA,0xA,0xA,0xA,0xA,0xA,0xA}}");
Assert.AreEqual<Guid>(Result, ResultValue);

See above code.