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Exporting Overview

Since Q3 2011 the Telerik RadTreeList can export your data to PDF after a call to its ExportToPdf() method.

Export to Excel functionality is added since Q1 2012. The corresponding method is ExportToExcel().

Common properties

In addition to the export format's specific properties, the ExportSettings group exposes several common properties:

ExportMode - this is an enumeration with four possible values described below:

  • DefaultContent - the whole data and content of the RadTreeList are sent for export,without removing or replacing anything;

  • RemoveControls - removes all controls that implement the IButton,ITextBox, ICheckBox and IScriptControl interfaces;

  • ReplaceControls - tries to replace all controls that implement the IButton,ITextBox, ICheckBox and IScriptControl interfaces with their text;

  • RemoveAll - removes all non-text controls.

IgnorePaging - when you enable it, the RadTreeList will rebind before export in order to fetch all the data from your data source.

OpenInNewWindow - by default, the exported file will be handled by the program associated with the appropriate file type. If you prefer to give the user the option to choose whether to save, open (inline) or cancel, you can enable this property.

Even if you set OpenInNewWindow="false" , that does not guarantee that the file will be opened inside the browser window.The way the exported file will be displayed inline depends on the OS / browser settings.The end-user could manage the file extensions with programs like NirSoft's FileTypesMan. For browsers, other than Internet Explorer , you should use the built-in settings.

FileName - This is helpful when you want to give a predefined name for your file. Please note that the file name cannot be longer than 256 symbols. Unicode names are not supported out-of-the-box for Internet Explorer 6 and 7. Of course you can manually encode the file name and it will be shown properly in the "Save" dialog (OpenInNewWindow="true"):

HttpUtility.UrlEncode("unicode string", System.Text.Encoding.UTF8);

Internet Explorer ignores the FileName property when OpenInNewWindow is set to false .


OnExporting event

By the time the OnExporting event is raised, the Pdf / Excel output is already generated and ready for adding to the response.Although you cannot modify the contents on OnExporting, you can use this event to achieve some other tasks. For example to save the file on the server, send it via mail or preview it in another window.

Export from AJAX-enabled RadTreeList

The exporting feature works only with regular postbacks. This means that the asynchronous postback should be canceled when performing an export.More information is available in the corresponding help topic.

Exporting a large amount of data

We strongly recommend not to export large amounts of data since there is a chance to encounter an exception (Timeout or OutOfMemory) if more than one user tries to export the same data simultaneously. RadTreeList is not suitable for such scenarios and therefore we suggest that you limit the number of columns and rows.

Export in SharePoint webpart

There is a special flag (_spFormOnSubmitCalled) in SharePoint that prevents the form to be submitted twice. The flag is set when the form is submitted and then cleared when the response is received. When using the exporting functionality, this flag won't be cleared because the response is redirected and therefore all further postbacks will be blocked. Controls not functional after Export to Excel or Export to PDF of Telerik in Sharepoint Application page

Export in web farm

If you receive "Invalid ViewState" or similar exception in web farm scenario, you can try to copy the machinekey from yourweb.config to the machine.config of the web server.

Export over SSL

You might receive the following error message when using the export feature over SSL and Internet Explorer:

Internet Explorer cannot download ' file' from ' server' . Internet Explorer was not able to open this Internet site. The requested site is either unavailable or cannot be found. Please try again later.

In order to prevent this error add the following lines just before the exporting:


See Also

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