如何在Storyboard中使用ViewController的自定义init

Question

I have one storyboard in which all of my viewControllers are placed. I'm using StoryboardID as:

AddNewPatientViewController * viewController =[[UIStoryboard storyboardWithName:@"Main" bundle:nil] instantiateViewControllerWithIdentifier:@"addNewPatientVC"];
 [self presentViewController:viewController animated:YES completion:nil];

In AddNewPatientViewController I've added a custom init method or constructor you can say as:

-(id) initWithoutAppointment
{
    self = [super init];
    if (self) {
        self.roomBedNumberField.hidden = true;
    }
    return self;
}

So my question is by using the above wat of presenting view controller how can I init it with this custom init I've made.

I've tried doing this as areplacement of above code but it didn't work.

AddNewPatientViewController *viewController = [[AddNewPatientViewController alloc] initWithoutAppointment];
 [self presentViewController:viewController animated:YES completion:nil]; 

Answer 1

It's not the best idea to use this approach. At first, I want to suggest you to set this property after instantiation; it would be better

If you anyway want to make such constructor, you can place your code with instantiation to it, so it will look like

-(id) initWithoutAppointment
{
    self = [[UIStoryboard storyboardWithName:@"Main" bundle:nil] instantiateViewControllerWithIdentifier:@"addNewPatientVC"];
    if (self) {
        self.roomBedNumberField.hidden = true;
    }
    return self;
}

but it won't be a good code

EDITED

May be it's the question of style, but I would rather prefer not to do this because view controller doesn't have to know about UIStoryboard; if you want to have such method, it would be better to move it to some separate factory. If I chose to use this VC in other projects without Storyboard, or with storyboards, but with another name, it will be error-prone.

Answer 2

You can't have a storyboard call a custom initializer.

You want to override init(coder:) . That's the initializer that gets called when a view controller is created from a storyboard (or from a nib, for that matter.)

Your code might look something like this:

Objective-C:

- (instancetype)initWithCoder:(NSCoder *)aDecoder; {
    [super initWithCoder: aDecoder];
    //your init code goes here.
}

Swift:

required init?(coder: NSCoder)  {
  //Your custom initialization code goes here.
  print("In \(#function)")
  aStringProperty = "A value"
  super.init(coder: coder)
}

Note that in Swift your initializer must assign values to all non-optional properties before you call super.init, and that you must call super.init() (or in this case, super.init(coder:) .