List<T> 分页方式,泛型分页方式

protected List<T> ListPager<T>(List<T> DataSource, int CurrentPageIndex, int PageSize, string FilterExpression, refint count)
        {
            count =0;
            if (DataSource ==null|| DataSource.Count ==0)
                return DataSource;
            count = DataSource.Count;
            if (string.IsNullOrEmpty(FilterExpression))
            {
                int startIndex = CurrentPageIndex * PageSize;
                if (startIndex + PageSize > DataSource.Count)
                {
                    PageSize = DataSource.Count - startIndex;
                }
                return DataSource.GetRange(startIndex, PageSize);
            }
            else
            {
                DataTable dt = KingLib.DataHelper.ListToDataTable<T>(DataSource);
                DataView dv = dt.DefaultView;
                dv.RowFilter = FilterExpression;
                List<T> NewDataSource = KingLib.DataHelper.DataTableToList<T>(dv.ToTable());
                count = NewDataSource.Count;
                int startIndex = CurrentPageIndex * PageSize;
                if (startIndex + PageSize > NewDataSource.Count)
                {
                    PageSize = NewDataSource.Count - startIndex;
                }
                return NewDataSource.GetRange(startIndex, PageSize);
            }
        }