[Solved] Export to excel with third party library npoi issue - displaying two empty columns in the starting in the excel sheet

[Chetan]

We are using Radgrid with paging. But at the time of export we need to export all records (6000 row and 56 columns). If we use normal export it takes lot of time to export to excel. One more case is that we do not want to use HTML format for excel as it shows warning while opening. Hence we decided to go for third party library NPOI. we are referring to 

http://www.telerik.com/community/code-library/aspnet-ajax/grid/export-to-excel-with-third-party-library-npoi.aspx

One issue is that it is displaying two empty columns in the starting in the excel sheet. All columns are added runtime. I have checked and there is no extra column added. 

<telerik:RadGrid ID="grdDetailreport" runat="server" GridLines="None" AllowSorting="True"
    AllowPaging="True" PageSize="50" AllowCustomPaging="true" AllowFilteringByColumn="true"
    OnNeedDataSource="grdDetailreport_NeedDataSource" OnSortCommand="grdDetailreport_SortCommand"
    OnItemDataBound="grdDetailreport_ItemDataBound" Width="950px">
    <ClientSettings AllowDragToGroup="false">
        <Scrolling AllowScroll="True" UseStaticHeaders="True" FrozenColumnsCount="5" SaveScrollPosition="true">
        </Scrolling>
    </ClientSettings>
    <PagerStyle Mode="NextPrevNumericAndAdvanced" Position="Bottom"></PagerStyle>
    <MasterTableView RetrieveAllDataFields="false" AutoGenerateColumns="false" EnableColumnsViewState="true"
        AllowCustomSorting="true" CommandItemDisplay="Top" TableLayout="Auto">
        <CommandItemSettings ShowExportToExcelButton="false" ShowAddNewRecordButton="false"
            ShowRefreshButton="false" ExportToExcelText="Export to excel"></CommandItemSettings>
        <Columns>
        </Columns>
    </MasterTableView>
    <ExportSettings IgnorePaging="true">
        <Excel Format="Biff" ></Excel>
    </ExportSettings>
</telerik:RadGrid>

[Kostadin]

Hello Chetan,

I would suggest you to use our latest export format (Biff) which won't trigger a warning message as with the HTML format. You could check the following live example and the related resources tab for additional information. If you still experience a performance issue you could use the ExportInfrastructure and export the data directly from the datasource as it is demonstrated in the following code library.

Regards,
Kostadin
the Telerik team

[Chetan]

How is its performance. Will it be able to export 7000 records efficiently? 

[Kostadin]

Hello Chetan,

If you use the ExportInfrastructure it will be faster then the Biff export format as the data is exported directly from the datasource. But I believe that both methods will handle to export such amount of data.

Kind regards,
Kostadin
the Telerik team