GridView固定行以后的翻页问题

<asp:GridView ID="gvProgram" runat="server" AllowPaging="True" 

    AutoGenerateColumns="False" DataKeyNames="ID" 

    DataSourceID="FileDataSource" OnDataBound="gvProgram_DataBind" 

    OnPageIndexChanging="gvProgram_PageIndexChanging" OnRowCommand="gvProgram_RowCommand" 

    Height="498px" Width="531px" PageSize="18" OnRowDataBound="gvProgram_RowDataBound"  

    >

    <PagerTemplate>

        <table width="100%">

            <tr>

                <td>

                    <asp:ImageButton ID="imageFirst" CommandName="Page"  CommandArgument="First"  runat="server"   />

                    <asp:ImageButton ID="imagePrevious" CommandName="Page" CommandArgument="Prev"  runat="server"/> 

                    <asp:ImageButton ID="imageNext" CommandName="Page" CommandArgument="Next" runat="server" />

                    <asp:ImageButton ID="imageLast" CommandName="Page" CommandArgument="Last" runat="server"/>

           </td>

            </tr>

        </table>      

    </PagerTemplate>

    <Columns>

        <asp:BoundField DataField="FileName" HeaderText="标题" >

        </asp:BoundField>

        <asp:BoundField DataField="FileSize" HeaderText="文件大小">

        </asp:BoundField>

    </Columns>

</asp:GridView>

<asp:ObjectDataSource ID="FileDataSource" runat="server" 

    SelectMethod="GetListByFileTypeAndHost" TypeName="BLLFile">

    <SelectParameters>

        <asp:Parameter DefaultValue="02" Name="fileType" Type="String" />

        <asp:Parameter DefaultValue="00" Name="host" Type="String" />

    </SelectParameters>

</asp:ObjectDataSource>

      protected void gvProgram_RowDataBound(object sender, GridViewRowEventArgs e)

        {

            if (e.Row.RowType == DataControlRowType.DataRow)

            {

                // 计算自动填充的行数

                numCount++;

            }

            if (e.Row.RowType == DataControlRowType.Footer)

            {

                // 计算完毕，在此添加缺少的行

                int toLeft = this.gvProgram.PageSize - numCount;

                int numCols = this.gvProgram.Rows[0].Cells.Count;

                DataControlRowState rowState = (this.gvProgram.Rows[numCount - 1].RowState);



                for (int i = 0; i < toLeft; i++)

                {

                    // 正确显示交叉行样式

                    rowState = (i % 2 != 0) ? DataControlRowState.Alternate : DataControlRowState.Normal;



                    GridViewRow row = new GridViewRow(-1, -1, DataControlRowType.EmptyDataRow, rowState);

                    for (int j = 0; j < numCols; j++)

                    {

                        TableCell cell = new TableCell();

                        cell.Text = " ";

                        row.Cells.Add(cell);

                    }

                    this.gvProgram.Controls[0].Controls.AddAt(numCount + 1 + i, row);

                }

            }

        }



  protected void gvProgram_PageIndexChanging(object sender, GridViewPageEventArgs e)

        {

            int newPageIndex = 0;

           // 当点击first, last, previous and next按钮时处理

                newPageIndex = e.NewPageIndex;

            //  对PageIndex溢出处理

            newPageIndex = newPageIndex < 0 ? 0 : newPageIndex;

            newPageIndex = newPageIndex >= this.gvProgram.PageCount ? this.gvProgram.PageCount - 1 : newPageIndex;

            // 更新PageIndex

            this.gvProgram.PageIndex = newPageIndex;

        }