Creates a thumbnail and adds it to the collection of thumbnail items.
Parameters
- filename
- A string value which represents the file containing the thumbnail.
- pageNumber
- An integer value which represents the page in the image file for the current thumbnail.
- type
- A ThumbnailType which represents the type of thumbnail. If a parent or sub directory is specified, the PageNumber parameter is ignored and the Filename parameter should contain the directory path.
Return Value
The created thumbnail item.