I have a PageViewController that has 3 child views contained within. I would like to see a simple Objective-C example using protocols/delegates for how I can trigger a method of the PageViewController when a user clicks a button in the child view controllers?
What you want is a simple delegation. You can create a page based project which will generate the code for you. After that create the protocol you want with its methods and add a delegate property to the Page child view controller. The only change you need to make is inside the pageViewController:viewControllerBeforeViewController and pageViewController:viewControllerAfterViewController methods. Before you return the page child controller there set also the delegate and implement the methods from the protocol.
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My app header is currently a full width, 65pt height UIView which I then use as a generic header for all pages.
class AppHeader: UIView {
...
}
Then, in my Main.storyboard I have a UIViewController with a View from the object library which has its class specified as AppHeader.
My AppHeader (UIView) has multiple buttons which should, if clicked, take you to from the page/controller you're currently on to another.
From the AppHeader class I do not have access to use the present method to show another controller as its not within scope.
Here is my AppHeader.xib:
How can I resolve this?
This is very bad behaviour, you should not use a UIView as a header. You should add a Navigation View Controller as the first view controller of your app. Navigation view controller has the navigation bar where you can put the buttons you want there. From that ones, you will be able to push or present other view controllers.
Check the official documentation: https://developer.apple.com/library/content/documentation/WindowsViews/Conceptual/ViewControllerCatalog/Chapters/NavigationControllers.html
Make your AppHeader view a custom subclass of UIView if it isn't already. Wire the actions on the button to IBAction methods in the view.
Create a protocol AppHeaderDelegateProtocol. Give your AppHeader class a weak delegate property. Define methods in that protocol that let the AppHeader notify it's owning view controller about button presses.
Implement your AppHeaderDelegateProtocol in view controllers that will contain instances of AppHeader.
Connect the delegate property to each instance of AppHeader's owning view controller.
That should do it.
You can create a protocol - call it AppHeaderDelegate or something - and set up your other viewControllers to adopt that protocol. You could define functions to let your delegate know that a certain button was pressed, and your delegate viewController can react to that by presenting the correct view controller.
Apple's docs on protocols here.
Alternatively, you can use NotificationCenter to broadcast notifications to let subscribers know that a certain button was pressed, and have your viewControllers listening for these notifications and reacting to them accordingly. You have to manage when classes start/stop listening, though, as you may have several objects trying to react to a single notification.
I have a UIView which I am using as a seperate module and can include it anywhere I want to. Now I want to navigate to a UIViewController on click of the button inside the UIView.
Hope this is pretty clear.
Short answer: You shouldn't. You need to read up on the MVC design pattern. A UIView is a view object. You are trying to add controller behavior to a view object.
You should take a look at parent/child view controllers, container views, and embed segues. You could easily create a view controller that manages a "tile" inside another view controller, and sends messages to it's parent when the user taps buttons. This is a very common way of doing things.
The best way to do this is to supply the ViewController to the view as a delegate, conforming to a protocol you create for it.
For instance, if you UIView is used to pick an image, then the delegate should have a method akin to:
(void)view:(UIView*)view choseImage:(UIImage*)image;
Can any one explain when should we add a UIViewController as ChildViewController?
What is the benefits of adding it as ChildViewController instead of subView?
Please help me to understand the purpose of ChildViewController.
When you add a view controller as child view controller, the parent view controller will hold a strong pointer to the child view controller so it doesn't get released instantly. This does not automatically add child's view to parent's view. So you will have to call them both.
I only used it when I needed to create multiple view controllers to be inserted in another view controller and didn't need to directly access it.
its all about UI and code management if you are using subview to achieve what you want to implement inside your app you need to code for your view inside same viewcontrollers class but something interesting i found by creating childviewcontrollers.
empowered to work on a seprate viewcontroller will invoked along with its parent viewcontroller along with its seprate class.
infinite controllers that will be updated tapping a button.
Creation of childViewControllers can be achived by implementing containerView.
or you must have a look of this link hope its helpful to understand.
Is there any way that could send the value in Class of ViewController to Class of View?
Because I want to make a drawing board and I made a modal scene to set values about color, width .
I know how to send the value in modal scene to my ViewController , but now I need use those value in Class of View , or not Class of ViewController.
Sounds like you need to devise a protocol to open a delegation channel between the two classes. Then when the modal VC wants to send data to its delegate (its presenter, in this case), it can of its own volition.
The View Controller can have a reference to the View, therefore the View Controller can simply pass the values to View by calling a View's method or updating View's properties. This is a common pattern: View defines a Protocol and data/requests from View to ViewController go through this Protocol (the ViewController acts as delegate of View); and ViewController owns the View.
For inspiration on how to implement a farily decoupled design applying this pattern, you can have a look at documentation on UICollectionView and UICollectionViewController.
Other options, depending on what design you need, are Key-Value Observing or Notifications.
I have 2 Collections View Controller and I would like to swipe from the first to the second. Then, I am using the Swipe Component but it's not working on my application (not working at all).
Otherwise, I know how to use it between 2 simples View Controller Component but I would like to use it in Collections View Controller Component.
Do you know how can I do that?
I think the easiest way to do what you are asking, is to embed the view controllers in a UIPageViewController.
Initialize using – initWithTransitionStyle:navigationOrientation:options:
Set the initial view controller using – setViewControllers:direction:animated:completion:
Implement the datasource methods pageViewController:viewControllerBeforeViewController: and pageViewController:viewControllerAfterViewController:
Don't forget to set the datasource.