如何在Swift中从另一个类扩展中调用类函数

Question

So say if I have a Class A. Then I create a new swift file for class B where it would look like this:

extension Class A {

 public Class B: Superclass {

  public class func doSomething() { }

 }

}

Now how would I make the call to doSomething() ?

Answer 1

If you want to add an inner class to an existing class via an extension, you can do it like this:

public class A {

}

public extension A {

    public class B {

        public class func doSomething() {
            print("hello")
        }

    }

}

Note there is no Superclass involved.

Since doSomething is a class method, you can call it like this:

A.B.doSomething() // "hello"

If you are trying to define a subclass of A , then you should do this:

public class A {

}

public class B: A {

        public class func doSomething() {
            print("hello")
        }

}

B.doSomething() // "hello"

Answer 2

How do you feel about this:

 public class A {
        var innerClass = InnerClass()
 }

extension A {
    public class InnerClass {   
            public class func doSomething() { }
    }   
}

public class C {
    var test = A().innerClass
}