Custom Thumbnails and Previews with Quick Look on iOS

Where to Go From Here?

You can download the finished version of the RazeThumb project by using the Download Materials button at the top or bottom of this tutorial.

You’ve now learned how to create a Quick Look thumbnail and preview for supported file types and custom file types.

Here are some key points you covered in the process:

• Thumbnails are miniature representations of a file’s contents.
• The QuickLook framework can create thumbnails and previews for various standard file types, such as images, audio, video, text, PDFs and more.
• Using extensions, you can extend the QuickLook framework to support your own custom file types.
• Extensions allow all apps on the device to access their functionality.
• Extensions run separate from the app.
• You can attach the Xcode debugger to an extension during development.

If you want to learn more, there are many related topics you can explore:

• You can dive deeper into Apple’s documentation on QuickLook Thumbnailing or view Apple’s WWDC 2019 Quick Look Previews from the Ground Up video. Both provide more insight into the possibilities.
• Learn more about document previews in QuickLook Previews for iOS: Getting Started, which covers editing tools and zoom transitions and other features of previews.
• Document-based apps make use of custom file types, and you can explore more about how to define custom file types and use them in Document Based Apps Tutorial: Getting Started.
• See what other extensions are provided by Apple on the Apple Developer website.

We hope you enjoyed this tutorial. If you have any questions or comments, please join the forum discussion below!