Sequential Guid Generator C#

Question

Is there any way to get the functionality of the Sql Server 2005+ Sequential Guid generator without inserting records to read it back on round trip or invoking a native win dll call? I saw someone answer with a way of using rpcrt4.dll but I'm not sure if that would be able to work from my hosted environment for production.

Edit: Working with @John Boker's answer I attempted to turn it into more of a GuidComb generator instead of being dependent on the last generated Guid other than starting over. That for the seed instead of starting with Guid.Empty that I use

public SequentialGuid()
{
    var tempGuid = Guid.NewGuid();
    var bytes = tempGuid.ToByteArray();
    var time = DateTime.Now;
    bytes[3] = (byte) time.Year;
    bytes[2] = (byte) time.Month;
    bytes[1] = (byte) time.Day;
    bytes[0] = (byte) time.Hour;
    bytes[5] = (byte) time.Minute;
    bytes[4] = (byte) time.Second;
    CurrentGuid = new Guid(bytes);
}

I based that off the comments on

// 3 - the least significant byte in Guid ByteArray 
        [for SQL Server ORDER BY clause]
// 10 - the most significant byte in Guid ByteArray 
        [for SQL Server ORDERY BY clause]
SqlOrderMap = new[] {3, 2, 1, 0, 5, 4, 7, 6, 9, 8, 15, 14, 13, 12, 11, 10};

Does this look like the way I'd want to seed a guid with the DateTime or does it look like I should do it in reverse and work backwards from the end of the SqlOrderMap indexes? I'm not too concerned about their being a paging break anytime an initial guid would be created since it would only occur during application recycles.

Answer 1

this person came up with something to make sequential guids, here's a link

http://developmenttips.blogspot.com/2008/03/generate-sequential-guids-for-sql.html

Answer 2

First of all - what is a purpose for this?

I'm asking this because the whole purpose of Guid is to be random and unique. If you just need something incremental, you can use Int type field and set it to be AutoIncremental.

Answer 3

As far I know NHibernate have special generator, called GuidCombGenerator. You can look on it.