实例成员不能用于Class类型吗? [英] Instance member cannot be used on type Class?

问题描述

我正在尝试从Indicator类访问name变量，该类继承自Person.但是，我认为我没有正确地进行初始化.

I'm trying to access the name variable from Indicator class, which inherits from Person. However, I believe I'm not doing my initialization right.

我得到以下信息:'错误:实例成员'name'不能用于'Indicator'`类型.

I get the following: 'error: instance member 'name' cannot be used on type 'Indicator'`.

class Person {
    var name: String

    init(myName: String){
        self.name = myName
    }

    deinit {
        Indicator.letKnowPersonDeinitialized()
    }
}


class Indicator: Person {
    convenience init() {
        self.init()
    }

    static func letKnowPersonDeinitialized() {
        print("\(name)")
    }
}

推荐答案

您不能直接在静态方法中访问非静态内容.

You cannot access non-static stuff directly in a static method.

方法letKnowPersonDeinitialized是静态的，因为它已使用static修饰符进行了修改:

The method letKnowPersonDeinitialized is static because it is modified with the static modifier:

static func letKnowPersonDeinitialized() {
  ^
  |
here!
}

Person的name属性不是静态的，因为它没有被static修改.

The name property of Person is not static because it is not modified by static.

由于非静态成员属于该类的每个单独实例，而静态成员属于该类本身，因此静态成员无法直接访问非静态成员.他们只能在存在实例的情况下访问非静态成员.

Since non-static members belong to each individual instance of that class and static members belong to the class itself, static members have no direct access to non-static members. They can only access non-static members when an instance is present.

要解决您的问题，请在letKnowPersonDeinitialized方法中添加一个参数:

To solve your problem, add a parameter to the letKnowPersonDeinitialized method:

static func letKnowPersonDeinitialized(person: Person) {
    print(person.name)
}

然后在反初始化器中:

deinit {
    Indicator.letKnowPersonDeinitialized(self)
}

---

非常重要的东西:

我认为您的代码设计得不好.这不是您使用继承的方式.

---

VERY IMPORTANT STUFF:

I don't think your code is designed well. This is not how you use inheritance.

继承表示是一种".因此，如果Indicator继承自Person，则意味着指标是一种人.

Inheritance means "is a kind of". So if Indicator inherits from Person, it means that an indicator is a kind of person.

根据常识，指标不是人.因此，此处不适合使用继承.没什么意义.

According to common sense, an indicator is not a person. Therefore, it is not suitable to use inheritance here. It makes little sense.

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