Container Views and presenting child view controllers

Question

A question about container views in xCode with objective-C. When I add a container view to my project it is visible by default in it's parent view controller. My goal is for it to be invisible to start with and to present it via a UIButton with the

addChildViewController:

method. But for that I need it to not be there to begin with. I can fix this by setting it's view.alpha to 0, but it seems long winded, to have something that's visible and have to make it invisible to then make it visible again. It doesn't seem best practice. I've checked the doccumentation and found a lot of interesting things but nothing on this particular subject. Can anyone point me in the right direction? Thanks

---------------------------UPDATE----------------------------------------

This is what I've done so far. (there's a @property ChildViewController *vc in the h file with the required import). It's not working. As in, it's not hidding anything.

- (void)viewDidLoad {
    [super viewDidLoad];

    self.vc = [[ChildViewController alloc]init];
    [self addChildViewController:self.vc];
    [self.view addSubview:self.vc.view];
    self.vc.view.hidden = YES;
}

Yes you can hide child view after adding as child view and show it whenever you want. — Saqib Omer, Feb 29 '16 at 14:21
hmmm... I am getting this: "property access result unused getters should not be used for side effects"? my line: self.vc.view.hidden; — Paul, Feb 29 '16 at 14:37
Ok I will. I am finding this challenging. Presenting View Controllers I can do, but when it come to child view controllers... — Paul, Feb 29 '16 at 15:41
I have since understood the "property access result problem..." — Paul, Feb 29 '16 at 15:45

score 0 · Accepted Answer · answered Feb 29 '16 at 14:56

0

Hiding the View Controller by setting its alpha is totally fine. It has the advantage that your view controller is ready to go so the app will feel more responsive. The alternative is to use 'presentViewController' to actually add it (modally) to the view. Thats probably the more normal way but really either is fine. The only time it wouldnt be a good idea is if that view controller that you are show/hiding is very processor or memory intensive, and you need your app to be more efficient with resources, in which case you should present and dismiss it modally rather than show/hiding it with alpha.

answered Feb 29 '16 at 14:56

Luke Smith

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but I thought present view controller was not for child view controllers? I thought for child view controllers you had to use addChildViewControllers? – Paul Feb 29 '16 at 15:40
Hi Paul. 'childViewController' here is a bit problematic. A viewController is a viewController - there are no different kinds (except subclasses). A child view controller is presented in a way that means it has a parent, and is one of a set of children - but these are just relationships. Its still a view controller. You actually dont really need to worry about this. Just create a view controller, and modally present it - its the simplest way. – Luke Smith Mar 01 '16 at 07:50

Container Views and presenting child view controllers

1 Answers1