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Thumbnails

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Image Thumbnails

ASPxFileManager automatically creates thumbnails for image files with the following file extensions:

  • bmp
  • gif
  • ico
  • jpg
  • jpeg
  • png

For better performance, these content-based thumbnails are stored in the location specified via the FileManagerSettings.ThumbnailFolder property.

NOTE

The folder that contains thumbnails must be placed physically inside the application folder.

Default Thumbnails

ASPxFileManager provides the default thumbnails for some file types listed below.

File Extension

Default Thumbnail

txt

FileManager_PlainTextThumbnail

rtf

doc

docx

odt

FileManager_RichTextThumbnail

xls

xlsx

ods

FileManager_SpreadsheetThumbnail

ppt

pptx

odp

FileManager_PresentationThumbnail

pdf

FileManager_PdfThumbnail

other extensions, where thumbnails are not defined

FileManager_FileThumbnail

You can change the last thumbnail via the FileManagerImages.File property.

Custom Thumbnails

In addition to an automatically created and default thumbnail, ASPxFileManager allows you to provide custom thumbnails by handling the ASPxFileManager.CustomThumbnail server event. This event allows you to define a custom manner in which all or certain files should be visually represented in folders. Within the event's handler, a currently processed item can be accessed and identified by using the FileManagerThumbnailCreateEventArgs.Item property, and a custom thumbnail can be defined for the file via the FileManagerThumbnailCreateEventArgs.ThumbnailImage property.

In the example below, the CustomThumbnail event is handled to analyze file extensions and represent each file type using the corresponding custom thumbnail image.

public void ASPxFileManager1_CustomThumbnail(object source, DevExpress.Web.FileManagerThumbnailCreateEventArgs e) {
        switch(((FileManagerFile)e.Item).Extension) {
            case ".avi":
                e.ThumbnailImage.Url = "Images/movie.png";
                break;
            case ".zip":
                e.ThumbnailImage.Url = "Images/archive.png";
                break;
            case ".txt":
                e.ThumbnailImage.Url = "Images/txt.png";
                break;
            case ".rtf":
                e.ThumbnailImage.Url = "Images/richtxt.png";
                break;
            case ".mp3":
                e.ThumbnailImage.Url = "Images/music.png";
                break;
            case ".xml":
                e.ThumbnailImage.Url = "Images/code.png";
                break;
        }
}
See Also