CATransaction completion being called immediately

I'm not sure if this really is the correct fix, but by setting the completion-block before adding the animation for the layer, the completion-block is consistently called at the correct time.

[CATransaction begin];[CATransaction setCompletionBlock:completionBlock];[self.view.layer addAnimation:self.dropAndBounceAnimation forKey:@"appearance"];[CATransaction commit];

You need to set the completion block before adding the animation.

[CATransaction begin];[CATransaction setValue:[NSNumber numberWithFloat: 1.0f] forKey:kCATransactionAnimationDuration];[CATransaction setCompletionBlock:^{// ... whatever you want to do when the animation is complete}];[self.googleMapsView animateToCameraPosition:[GMSCameraPosition                     cameraWithLatitude:LATITUDE                             longitude:LONGITUDE                                  zoom:ZOOM]];[CATransaction commit];

This must trigger the completion block after the completion of that animation on the view.

Here is Swift 3.0.1, Xcode 8 version:

CATransaction.begin()CATransaction.setCompletionBlock({  print("Transaction completed")})print("Transaction started")view.layer.add(dropAndBounceAnimation, forKey: "appearance")CATransaction.commit()