Virtualization in File Manager Control

5 Feb 20252 minutes to read

File Manager’s UI virtualization allows for the dynamic loading of a large number of directories and files in both the detailsView and largeIconsView without degrading performance.

Enable Virtualization

The virtualization of the File Manager control is based on the height and width of the viewport. The items will be loaded in both largeIconsView and detailsView based on the viewport size.

In order to enable virtualization, you must set the EnableVirtualization property to true.

The example below shows a large collection of files in the Documents and Text Documents folders.

<div class=" control-section">
    <div class="sample-container">
        <!-- File Manager virtualization feature sample -->
        <ejs-filemanager id="filemanager" enableVirtualization="true">
            <e-filemanager-ajaxsettings url="https://ej2-aspcore-service.azurewebsites.net/api/Virtualization/FileOperations"
                                        downloadUrl="https://ej2-aspcore-service.azurewebsites.net/api/Virtualization/Download"
                                        uploadUrl="https://ej2-aspcore-service.azurewebsites.net/api/Virtualization/Upload"
                                        getImageUrl="https://ej2-aspcore-service.azurewebsites.net/api/Virtualization/GetImage">
            </e-filemanager-ajaxsettings>
        </ejs-filemanager>
    </div>
</div>

The output will look like the image below.

Virtualization

Limitations for Virtualization

  • Programmatic selection using the selectAll method is not supported with virtual scrolling.

  • The keyboard shortcut CTRL+A will only select the files and directories that are currently visible within the viewport, rather than selecting all files and directories in the entire directory tree.

  • Selected file items are not maintained while scrolling to ensure optimal control performance.