快速访问容器按钮

Question

I am relatively new to Swift. Here is my question: I have a UIViewController that has a container in it. The container has its own ContainerViewController. The container is the header of the app and it has a button in it.

I would like to set the value of a Bool inside the UIViewController based on whether the button (inside the container) has been pressed or not.

I don't think passing a "mainVC" with a segue would make it: There is no point to make a segue as the two views are shown on the same screen.

Should I give both the view and its container the same ViewControllerClass?

Thank you very much for your time

Answer 1

There are different solutions:

1. Call a method on the ContainerViewController 's parentViewController (=UIViewController)
2. Use the responder chain:
   • Implement canBecomeFirstResponder() in the UIViewController (subclass) to return YES
   • implement a buttonPressed(sender:AnyObject) (or something) method in the parent view controller
   • call UIApplication.sharedApplication().sendAction("buttonPressed:", to: nil, from:self) from within the container view controller

This will allow the method to "travel" up the responder chain until it find a object that implements the buttonPressed() method. This solution can be useful if you want to reuse the header view in other view controllers.

3. Use the delegate pattern. Create a delegate property + protocol in the container view controller and have the parent vc set itself as delegate in the prepareForSegue() method that fires of the embed-segue. This also gets the reuse friendly stamp.

4. If you are using Storyboards then you can also use an Unwind Segue