[ios] Swift: Reload a View Controller

I need to refresh a view controller when a certain button is tapped. Simply activating viewDidLoad() does not seem to be working for what I need to do. However, when I leave the view controller then come back to it, it seems to work perfectly?

How can I refresh/reload a view controller as if I have left it then come back to it without ever actually leaving it?

Whatever code you are writing in viewDidLoad, Add that in viewWillappear(). This will solve your problem.

Swift 5.2

The only method I found to work and refresh a view dynamically where the visibility of buttons had changed was:-

viewWillAppear(true)

This may be a bad practice but hopefully somebody will leave a comment.

You shouldn't call viewDidLoad method manually, Instead if you want to reload any data or any UI, you can use this:

override func viewDidLoad() {
    super.viewDidLoad();

    let myButton = UIButton()

    // When user touch myButton, we're going to call loadData method
    myButton.addTarget(self, action: #selector(self.loadData), forControlEvents: .TouchUpInside)

    // Load the data
    self.loadData();
}

func loadData() {
    // code to load data from network, and refresh the interface
    tableView.reloadData()
}

Whenever you want to reload the data and refresh the interface, you can call self.loadData()

View Life Cycle

it will load ViewWillAppear everytime you open the view. above is the link to the picture View Controller Lifecycle.

viewWillAppear()—Called just before the view controller’s content view is added to the app’s view hierarchy. Use this method to trigger any operations that need to occur before the content view is presented onscreen. Despite the name, just because the system calls this method, it does not guarantee that the content view will become visible. The view may be obscured by other views or hidden. This method simply indicates that the content view is about to be added to the app’s view hierarchy.

https://developer.apple.com/library/archive/referencelibrary/GettingStarted/DevelopiOSAppsSwift/WorkWithViewControllers.html

If you need to update the canvas by redrawing views after some change, you should call setNeedsDisplay.

Thank you @Vincent from an earlier comment.

This might be a little late, but did you try calling loadView()?

If you are using a navigation controller you can segue again to the current UIViewController and it will be refreshed.

In Swift 4:

self.view.layoutIfNeeded()