Thumbnails
- 2 minutes to read
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 |
|
rtf doc docx odt |
|
xls xlsx ods |
|
ppt pptx odp |
|
| |
other extensions, where thumbnails are not defined |
|
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;
}
}