Why can I call a private method of another instance of the same type outside of that instance? [duplicate]

问题

This question already has answers here:

Why and how does C# allow accessing private variables outside the class itself when it's within the same containing class? (3 answers)

Closed last year.

If I have ObjectA, and it has a private method GetPrice() and also has a "parent" field of the same type, why am I able to call GetPrice() on the parent instance from within the child instance?

Example:

private decimal GetPrice()
{
    ObjectA parent = Parent;

    if(parent != null)
    {
        return parent.GetPrice(); // Why is this OK?
    }

    return 0;
}

回答1:

Because private means "not accessible to other types", not "not accessible to other instances".

回答2:

Because private scope is limited to the class, not the instance as defined in the C# spec:

1.6.2 Accessibility Each member of a class has an associated accessibility, which controls the regions of program text that are able to access the member. There are five possible forms of accessibility. These are summarized in the following table.

Accessibility       Meaning   

public              Access not limited   
protected           Access limited to this class or classes derived from this class  
internal            Access limited to this program   
protected internal  Access limited to this program or classes derived from this class    
private             Access limited to this class

回答3:

An access modifier is related to it's implementing class/type not to instances of that class

来源：https://stackoverflow.com/questions/13195891/why-can-i-call-a-private-method-of-another-instance-of-the-same-type-outside-of