SqlTimeSpan

using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;

[Serializable]
[SqlUserDefinedType(Format.UserDefined
    , MaxByteSize = 9
    , IsByteOrdered = true)]
public struct LongUdt : INullable, IBinarySerialize
{
    private bool m_Null;
    public long _longField;

    public override string ToString()
    {
        return _longField.ToString();
    }

    public bool IsNull
    {
        get
        {
            // Put your code here
            return m_Null;
        }
    }

    public static LongUdt Null
    {
        get
        {
            LongUdt h = new LongUdt();
            h.m_Null = true;
            return h;
        }
    }

    public static LongUdt Parse(SqlString s)
    {
        if (s.IsNull)
            return Null;
        LongUdt u = new LongUdt();
        u._longField = long.Parse(s.Value);
        return u;
    }

   
    #region IBinarySerialize Members

    void IBinarySerialize.Write(System.IO.BinaryWriter w)
    {
        // WARNING! No Null check here.

        // ----------------------------------
        // Int64 (long) version
        //long u = var1;
        //w.Write(u);


        // ----------------------------------
        // UInt64 (ulong) version        
        ulong u = (ulong)(_longField + long.MaxValue + 1);
        w.Write(u);
    }

    void IBinarySerialize.Read(System.IO.BinaryReader r)
    {
        // WARNING! No Null check here.

        // ----------------------------------
        // Int64 (long) version
        //var1 = r.ReadInt64();

        // ----------------------------------
        // UInt64 (ulong) version   
        ulong u = r.ReadUInt64();
        _longField = (long)(u - long.MaxValue - 1);
    }
    #endregion
}