requestThumbnail()
Requests a thumbnail for the item.
Declaration
func requestThumbnail()Discussion
If a thumbnail is not readily available, accessing this property will send a message to the device requesting a thumbnail for the file. The delegate of the device will be notified via method cameraDevice(_:didReceiveThumbnail:for:error:), if this method is implemented by the delegate. Execution of the delegate callback will occur on the main thread.