Generates the best possible thumbnail representation for a file and calls a handler upon completion.
- iOS 13.0+
- macOS 10.15+
- Mac Catalyst 13.0+
The request that contains information about the thumbnail that you want to create.
The completion handler to call when the thumbnail generation completes. It is always called when
QLThumbnailfinishes the generation of a requested thumbnail.
The completion handler takes the following parameters:
The most representative version of the requested thumbnail or
QLThumbnailwas unable to generate a thumbnail.
An error object that indicates why the thumbnail generation failed, or
nilif the thumbnail generation succeeded.