Question

MyPage.aspx:

<asp:TextBox ID="txtPageCount" runat="server" EnableViewState="true" ></asp:TextBox>
<rc:ReportControl id="ReportControl1" runat="server" />

ReportControl.ascx:

<div>
            <rsweb:ReportViewer ID="ReportViewer1" runat="server" CssClass="ReportViewer" AsyncRendering="false"
                OnPreRender="RptViewer_PreRender" EnableViewState="true" Width="100%" PageCountMode="Actual"
                WaitMessageFont-Size="1.2em" ShowToolBar="true" Visible="true"
                InteractiveDeviceInfos="(Collection)">  
                <LocalReport></LocalReport>           
            </rsweb:ReportViewer>

</div>

After report processing(RptViewer_PreRender), in Render event of MyPage.aspx, I’m updating value of txtPageCount.

protected override void Render(HtmlTextWriter writer)
{
    base.Render(writer);
    TextBox pageCount = new TextBox();
    pageCount = (TextBox)RtDialysisSummary.FindControl("txtPageCount");

    pageCount.Text = Convert.ToString(ReportViewer1.TotalPages);
}

The value of textbox is not updating.

Answer 1

Try updating the value before you call base.Render(writer); like below

protected override void Render(HtmlTextWriter writer)
{
    TextBox pageCount = new TextBox();
    pageCount = (TextBox)RtDialysisSummary.FindControl("txtPageCount");

    pageCount.Text = Convert.ToString(ReportViewer1.TotalPages);
    base.Render(writer);
}