Change the alpha value of the navigation bar

Question

Is this possible?

I want to change the alpha value of the navigation bar in my view controller (in an animation), but if I do self.navigationController.navigat

Answer 1

If you just want to get rid of the navigationBar in an animated way you could do:

[self.navigationController setNavigationBarHidden:YES animated:YES];

If you want to control the animation and its necessary to set the alpha to 0.0, read on:

The "black box" you are seeing is from the underlying view or window. If you just want your views color instead of the "black box" do:

self.navigationController.view.backgroundColor = self.view.backgroundColor;

[UIView animateWithDuration:1.0 delay:1.0 options:0 animations:^{
    self.navigationController.navigationBar.alpha = 0.0;
} completion:NULL];

If you want your actual view to be where the navigationBar was, you need to increase the height of your view:

[UIView animateWithDuration:1.0 delay:1.0 options:0 animations:^{
    self.navigationController.navigationBar.alpha = 0.0;

    CGFloat navigationBarHeight = self.navigationController.navigationBar.frame.size.height;

    CGRect frame = self.view.frame;
    frame.origin.y -= navigationBarHeight;
    frame.size.height += navigationBarHeight;
    self.view.frame = frame;
} completion:NULL];