How to add a UIView above the current UITableViewController

Question

I have difficulty adding a subview (UIView) from within the viewDidLoad method of a UITableViewController

This works:

[self.view addSubview:self.prog         


        

Answer 1

So 7 years have passed since my original answer, and I happen to stumble upon this problem again. Let's solve this properly once and for all:

1. In viewDidLoad, add your subview to the (table) view.
2. Pin the constraints relative to the safe area layout guide. This stops it from scrolling with the table contents (as pointed out in cornr's answer).
3. In viewDidLayoutSubviews, bring the subview to the front. This ensures it doesn't get lost behind the table separators.

Swift:

override func viewDidLoad() {
    super.viewDidLoad()

    // 1.
    view.addSubview(mySubview)

    // 2. For example:
    mySubview.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint.activate([
        mySubview.widthAnchor.constraint(equalToConstant: 100),
        mySubview.heightAnchor.constraint(equalToConstant: 100),
        mySubview.centerXAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerXAnchor),
        mySubview.centerYAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerYAnchor)
    ])
}

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    // 3.
    view.bringSubviewToFront(mySubview)
}

Objective-C:

- (void)viewDidLoad
{
    [super viewDidLoad];

    // 1.
    [self.view addSubview:self.mySubview];

    // 2.
    self.mySubview.translatesAutoresizingMaskIntoConstraints = false;
    [NSLayoutConstraint activateConstraints:@[
        [self.mySubview.widthAnchor constraintEqualToConstant:100],
        [self.mySubview.heightAnchor constraintEqualToConstant:100],
        [self.mySubview.centerXAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.centerXAnchor],
        [self.mySubview.centerYAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.centerYAnchor]
    ]];
}

- (void)viewDidLayoutSubviews
{
    [super viewDidLayoutSubviews];

    // 3.
    [self.view bringSubviewToFront:self.mySubview];
}

Phew, glad that's done! Seeing how much saner this answer is, I'll omit my original answer.

Fun fact: 7 years on and I'm still an iOS developer.