在实例方法中调用类型方法 [英] Calling Type Methods Within An Instance Method

问题描述

Apple对类型（类）方法有一个很好的解释 Here 。

Apple has a nice explanation of Type (Class) Methods Here.

但是，他们的示例如下所示：

However, their example looks like this:

class SomeClass {
    class func someTypeMethod() {
        // type method implementation goes here
    }
}
SomeClass.typeMethod()

我看到这个完全相同的例子到处都是鹦鹉学舌。

I see this exact same example parroted everywhere.

然而，我我需要在我的类的一个实例中调用我的Type方法，而这似乎无法计算。

However, I need to call my Type Method from within an instance of my class, and that don't seem to compute.

我必须做错事，但我注意到Apple还不支持Class Properties :(。我想知道我是否会去干井用水。

I MUST be doing something wrong, but I noticed that Apple does not yet support Class Properties :(. I am wondering if I am going to a drywell for water.

这是我尝试过的（在操场上）：

Here is what I have tried (in a playground):

class ClassA
{
    class func staticMethod() -> String { return "STATIC" }

    func dynamicMethod() -> String { return "DYNAMIC" }

    func callBoth() -> ( dynamicRet:String, staticRet:String )
    {
        var dynamicRet:String = self.dynamicMethod()
        var staticRet:String = ""

//        staticRet = self.class.staticMethod() // Nope
//        staticRet = class.staticMethod() // No way, Jose
//        staticRet = ClassA.staticMethod(self) // Uh-uh
//        staticRet = ClassA.staticMethod(ClassA()) // Nah
//        staticRet = self.staticMethod() // You is lame
//        staticRet = .staticMethod() // You're kidding, right?
//        staticRet = this.staticMethod() // What, are you making this crap up?
//        staticRet = staticMethod()  // FAIL

        return ( dynamicRet:dynamicRet, staticRet:staticRet )
    }
}

let instance:ClassA = ClassA()
let test:( dynamicRet:String, staticRet:String ) = instance.callBoth()

有没有人能为我提供线索？

Does anyone have a clue for me?

推荐答案

var staticRet:String = ClassA.staticMethod()

这有效。它不需要任何参数，因此您不需要传入任何参数。你也可以像这样动态获得ClassA：

This works. It doesn't take any parameters so you don't need to pass in any. You can also get ClassA dynamically like this:

Swift 2

var staticRet:String = self.dynamicType.staticMethod()

Swift 3

var staticRet:String = type(of:self).staticMethod()

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