iphone persistent button on all views

I have a navigation app that has many screens the user navigates to. A handful of views manages these screens dynamically. What I want to try to do is add a button that will always show up on every screen the user views. I need to do 开发者_Python百科this so that the user is always able to preform the action associated with the button regardless of where they are in the app.

Is it possible to achieve this by adding this button only once and having it passed between views like my navigation bar is? Or do I just have to man up and add this button and its functionality to every single view file I have?

Thanks

I would say it probably depends on what the button does. If the button is generic to all views, meaning it affects all views the same exact way so no customization for a given view is needed, then a way to do this would be to include the function in the App Delegate or as a subclass to your Navigation controller.

You can then use the rightBarButtonItem to always show the same button and just access that method. You would just have to add code for the rightBarButtonItem in each viewDidLoad (but they'd all be the same).

I did something similar to this with an "Upgrade" button on one project. Since all the button does is launch the AppStore to the paid version, it's independent of all views and I can place it anywhere.

You can put the button on the navigation bar if you want. Alternately, the more generic way to do this would be to split your single view into two views. One is small and only contains your button but always stays on the screen. The second is your workspace and you swap in and out the views that are displaying the current content. You'll note that this is the way the navigation controls and tab-bar controls work. The last way to do this would be to put different buttons, in the same place, on each view and have them all trigger the same action. As far as the user is concerned this looks like the same button. Disadvantage here is that you can't alter the button across all views in a simple manner.