MSSQL paging + sorting + filtering

CREATE PROCEDURE [TestTable_GetPagedAndSortedAndFiltered]
(
 @startRowIndex int,
 @maximumRows int,
 @order nvarchar(50),
 @ID int = null,
 @Name nvarchar(50) = null,
 @Size int = null,
 @From datetime = null,
 @To datetime = null
) 
AS
BEGIN

declare @lastKey int
declare @lastAsc sql_variant
declare @lastDesc sql_variant

set rowcount @startRowIndex

select
@lastAsc = OrderAsc,
@lastDesc = OrderDesc,
@lastKey = OrderKey
from 
(
select *, 
ID as OrderKey,
case @order
 when 'ID' then cast(ID as sql_variant)
 when 'Name' then cast(Name as sql_variant)
 when 'Size' then cast(Size as sql_variant)
 when 'Created' then cast(Created as sql_variant)
 else ID
END as OrderAsc,
case @order
 when 'ID DESC' then cast(ID as sql_variant)
 when 'Name DESC' then cast(Name as sql_variant)
 when 'Size DESC' then cast(Size as sql_variant)
 when 'Created DESC' then cast(Created as sql_variant)
END as OrderDesc
from TestTable
where 
((@ID is null) or (@ID = ID))
and
((@Name is null) or (Name like @Name))
and
((@Size is null) or (@Size = Size))
and
((@From is null) or (@From < Created))
and
((@To is null) or (dateadd(day,1,@To) > Created))
) as T
order by OrderAsc,OrderDesc desc,OrderKey

set rowcount @maximumRows

select *
from 
(
select *, 
ID as OrderKey,
case @order
 when 'ID' then cast(ID as sql_variant)
 when 'Name' then cast(Name as sql_variant)
 when 'Size' then cast(Size as sql_variant)
 when 'Created' then cast(Created as sql_variant)
 else ID
END as OrderAsc,
case @order
 when 'ID DESC' then cast(ID as sql_variant)
 when 'Name DESC' then cast(Name as sql_variant)
 when 'Size DESC' then cast(Size as sql_variant)
 when 'Created DESC' then cast(Created as sql_variant)
END as OrderDesc
from TestTable
where
((@ID is null) or (@ID = ID))
and
((@Name is null) or (Name like @Name))
and
((@Size is null) or (@Size = Size))
and
((@From is null) or (@From < Created))
and
((@To is null) or (dateadd(day,1,@To) > Created))

)as T
where
(
 @lastAsc is null
 and
 @lastDesc is null
 and
 @lastKey is null
)
or
(
 @lastAsc is not null
 and
 (
  OrderAsc > @lastAsc
   or
  OrderAsc = @lastAsc
   and
  OrderKey >= @lastKey
 )
)
or
(
 @lastDesc is not null
 and
 (
  OrderDesc < @lastDesc
   or
  OrderDesc = @lastDesc
   and
  OrderKey >= @lastKey
 )
)
order by OrderAsc,OrderDesc desc,OrderKey

set rowcount 0

END