Creates a thumbnail of a custom file type for a specific request.
- iOS 11.0+
- macOS 10.15+
- Mac Catalyst 13.0+
The request that contains information about the thumbnail that you need to provide, such as the URL to the file.
The completion handler to call when you finish creating a thumbnail. Call the completion handler with a
QLThumbnailif you can provide a thumbnail or with an
NSErrorif you can’t create a thumbnail.
The platform doesn’t draw a thumbnail if you pass an
errorto the handler or the
You can call the handler asynchronously after the method has returned.
The object containing information about the thumbnail image that the platform uses to draw the thumbnail.
An error object that indicates why the thumbnail generation failed, or
nilif the thumbnail generation succeeded.