How do I obtain the height of UINavigationBar.navigationItem programmatically?

I am creating a custom UIToolbar to use as a UIView in the UINavigationBar.navigationitem.titleView property. I would like to size the toolbar height to that of the .navigationitem by obtaining the current height of the .navigationitem rather than hard code it. Is there a way to obtain the 开发者_如何学Cheight value?

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Not sure if this is what you need.

self.navigationController.navigationBar.frame.size.height