It is possible to animate the alpha with a duration like so:
[UIView animateWithDuration:0.5 animations:^{
[self.navController setNeedsStatusBarAppearanceUpdate];
}];
But would it be possible through CoreAnimation and UIKit to control the alpha with display link or gestures as a driver instead? I'm talking about brief moments while doing a gesture driver transition from one controller to another.
Sometimes a plain animateWithDuration just isn't what I want.
Since the code below works, you can change the alpha at will.
@IBAction func sliderValueChanged(sender: UISlider) {
if let navigationController = self.navigationController {
navigationController.navigationBar.alpha = CGFloat(sender.value)
}
}
If the question is about animating during a transition, and the timing is the issue, you then want to control that transition with the UIPresentationController, which provides timing information.
