GridView paging not working in Content aspx page

See more:

C#3.0

C#

ASP.NET

ASP.NET2

Hi All,

I'm using an aspx page that is inherited from master page. Have a GridView in the content page.
But GridView paging is not working. When I clicked on next page, nothing happened.
But it's working in normal ASPX page.

Here is my full code.

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder_Body" runat="server">
<asp:GridView ID="grdPdfShow" runat="server" AllowSorting="True" AutoGenerateColumns="False"
                        OnPageIndexChanging="grdPdfShow_PageIndexChanging" 
                        AllowPaging="True" PageSize="2">
                        <Columns>
                            <asp:BoundField DataField="FileId" HeaderText="Serial No" />
                            <asp:TemplateField>
                                <ItemTemplate>
                                    <asp:Label ID="lblFileType" runat="server" Text='<%# Eval("FileType") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField HeaderText="File Content">
                                <ItemTemplate>
                                    <asp:TextBox ID="txtFileContent" runat="server" ReadOnly="True" 
                                        TextMode="MultiLine" Text='<%# Eval("FileContent") %>' Height="60px" 
                                        Width="200px"></asp:TextBox>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField HeaderText="File Name">
                                <ItemTemplate>
                                    <asp:LinkButton ID="lnkBtnFileName" runat="server" 
                                        Text='<%# Eval("FileName") %>' ToolTip="View File" 
                                        onclick="lnkBtnFileName_Click"></asp:LinkButton>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField HeaderText="">
                                <ItemTemplate>
                                    <asp:LinkButton ID="lnkBtnDownload" runat="server" 
                                        onclick="lnkBtnDownload_Click">Download</asp:LinkButton>
                                </ItemTemplate>
                            </asp:TemplateField>
                        </Columns>
                        <PagerSettings FirstPageText="First" LastPageText="Last" 
                            Mode="NextPreviousFirstLast" NextPageText="Next" PreviousPageText="Previous" />
                    </asp:GridView>
</asp:Content>

And Code behind :

protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                grdPdfShow.DataSource = GetDataForPdfGridView();
                grdPdfShow.DataBind();
            }
        }

        private DataTable GetDataForPdfGridView()
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("FileId", typeof(int));
            dt.Columns.Add("FileType", typeof(string));
            dt.Columns.Add("FileContent", typeof(string));
            dt.Columns.Add("FileName", typeof(string));
            dt.Columns.Add("FilePath", typeof(string)); // not shown in Grid.
            int i = 1;
            foreach (var path in Directory.GetFiles(Server.MapPath("~/Resources/Articles/"), "*.pdf", SearchOption.TopDirectoryOnly))
            {
                dt.Rows.Add(i, "pdf", "Hello World", Path.GetFileName(path).ToString(), "~/Resources/Articles/" + Path.GetFileName(path));
                i++;
            }
            return dt;
        }

        protected void grdPdfShow_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            grdPdfShow.PageIndex = e.NewPageIndex;
            grdPdfShow.DataSource = GetDataForPdfGridView();
            grdPdfShow.DataBind();
            //grdPdfShow.PageIndex = e.NewPageIndex;
        }

Please help me ASAP. Thanks in Advance.