Instance member cannot be used on type Class?

问题

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.

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)")
}
}

回答1:

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

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

static func letKnowPersonDeinitialized() {
  ^
  |
here!
}

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

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.

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

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

And in the deinitializer:

deinit {
    Indicator.letKnowPersonDeinitialized(self)
}

VERY IMPORTANT STUFF:

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

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

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

来源：https://stackoverflow.com/questions/37201292/instance-member-cannot-be-used-on-type-class

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swift

init