2个或更多具有相同swift类崩溃的视图控制器

Question

Hello I have multiple veiwcontorllers in my storyboard and when they have the same class (for exmaple viewocntorller.swift) and code like changing background color they crash with

EXC_BAD_INSTRUCTION (code=EXC_1386_INVOP, subcode=0x0)

Is there some way to fix this without using separate .swift files for each viewcontroller

Here are screenshot

enter image description here

enter image description here

Has you can see the viewcontroller are in same class

Answer 1

it's not the error of viewController. It means that your button reference is not there. It's nil . Verify that it's properly created.
May be you've button outlet of one xib and not the other. and when for your xib (with no button), viewDidLoad is called, button is nil. If you have buttons in both, then properly attach outlet. otherwise, make this button optional

Answer 2

You don't have a button on your second view controller in your storyboard. Since you have an outlet to that button (the one on the first view controller) inside your code (linked to both viewcontrollers) and you specify a color for it your code will crash, because there is no button, calling a nil reference = crash.

To solve this you can add a button on the second view.

An outlet is not a basic optional, you are in fact telling the compiler that this button will NEVER be nil, that is what we call an Implicitly Unwrapped Optional.