问题
I need to have a few UIViewControllers that look very similar yet have different behaviours, so I thought I'd make a general UIViewController subclass with a xib, then subclass it when I need to, for those different UIViewController's that look alike.
I'm trying to achieve the following
UIViewController subclass (that has a xib file associated) -> and being able to subclass it as many times as i'd like (without additional xib files for the children)
what I've done so far :
xib file represents a UIViewController with multiple UI Elements.
I've set all the connections to file's owner @ xib file.
the subclass with the xib contains this @ init method:
self = [[[NSBundle mainBundle] loadNibNamed:
[NSString stringWithFormat:@"ParentViewController"]
owner:self options:nil] objectAtIndex:0];
when I connect the View property in the xib to file's owner I get an exception saying I can't have the View property connected to both parent and child UIViewControllers.
yet when the View property is only connected to the UIViewController that the xib is associated with, I get a blank screen, and that outlet isn't disconnectable.
If I instantiate the parent vc instead of the child, everything works fine, If everything is done programatically and not with a xib, also everything works fine.
since this UIViewController displays A LOT of UI elements, I'm trying to set it with a xib.
I just don't really understand how can I get the child ViewControllers to look like the parent's xib file and have their own additions and behaviours.
回答1:
If you only have an xib for the parent class (but none of the subclasses), you can just do this in your subclass init:
- (instancetype) init {
if (self = [super initWithNibName:@"ParentViewController" bundle:nil]) {
// init stuff for subclass
}
return self;
}
Here's an example project:
https://github.com/annabd351/SubClassFromParentNib
回答2:
If someone is looking for a Swift solution, you can use Convenience initializers on the subclass and initialise it using the super class xib.
In your subclass use the convenience initializer as:
class ChildController: BaseViewController {
convenience init() {
self.init(nibName: "BaseViewControllerXib", bundle: nil)
}
override func viewDidLoad() {
super.viewDidLoad()
}
}
And then when creating the child class object just use.
let childViewController = ChildController()
navigationController.pushViewController(childViewController, animated: true)
This way you can use the xib from the parent viewController.
来源:https://stackoverflow.com/questions/27336730/subclassing-a-subclassed-uiviewcontroller-that-has-a-xib