立即调用CATransaction完成

Question

我正在尝试在CAAnimation完成后执行完成块.但是,似乎在我的动画完成之前调用了动画块.但动画仍然正确.

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

dropAndBounceAnimation是position.y上的CAKeyFrameAnimation,具有固定的持续时间.

Answer 1

我不确定这是否是正确的修复,但通过在 为图层添加动画之前设置完成块,将在正确的时间始终调用完成块.

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

Answer 2

您需要在添加动画之前设置动画块.

[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];

这必须在视图上完成该动画后触发完成块.

Answer 3

这是Swift 3.0.1，Xcode 8版本：

CATransaction.begin()

CATransaction.setCompletionBlock({
  print("Transaction completed")
})

print("Transaction started")
view.layer.add(dropAndBounceAnimation, forKey: "appearance")

CATransaction.commit()