using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Value1".ToEnumStrict<Test>(new Exception("Value not supprted")));

        Console.WriteLine("Value".ToEnumStrict<Test>(new Exception("Value not supprted")));

    }

}

​

public enum Test

{

    Value1,

    Value2

}

​

public static class EnumExtenstions

{

    public static T ToEnumStrict<T>(this string str, Exception onFail) where T : struct, Enum

    {

        if (Enum.TryParse<T>(str, out var enumValue) && Enum.IsDefined(enumValue))

        {

            return enumValue;

        }

        else

        {

            throw onFail;

        }

    }

}