# CGImageSourceAnimationBlock The block to execute for each frame of an image animation. ``` typealias CGImageSourceAnimationBlock = (Int, CGImage, UnsafeMutablePointer) -> Void ``` ## Parameters `index` The index of the image in the file. `image` The image to display. `stop` A Boolean flag set to `false` on input. To stop the animation, set the value of this parameter to `true`. ## Discussion During the animation of an image, the system calls this block for each successive frame of the animation. Use this block to display the new image in your app’s interface, and to update any additional details. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)