C# - ref this(引用自己)

Question

假设我有一个C++代码:

class A {
    int x = 20;

    void Interact(A* Other) {
        if (x % 2 == 0) { Other->x++; x /= 2; } //some advanced operation
    }
public:
    void MakeInteraction(A* Other) {
        Interact(Other);
        Other->Interact(this);
    }
};

int main() {
    A a, b;
    a.MakeInteraction(&b);
}

问题是,如果我想在C#中做类似的东西,我遇到了障碍 - 当然我不需要使用指针,但我不能使用this对象的引用:

class A
{
    int x = 20;
    void Interact(ref A Other)
    {
        if (x % 2 == 0) { Other.x++; x /= 2; }
    }
    public void MakeInteraction(ref A Other)
    {
        Interact(ref Other); //works
        Other.Interact(ref this); //doesn't work
        Other.Interact(this); //still doesn't work
        A a = this; 
        Other.Interact(ref a);
        this = a; //REALLY? THIS DOESN'T WORK TOO?!
    }
}

我很生气,因为我认为C#纠正了C++的缺陷,并留下了与最初的C++一样多的选项,减去了指针.现在看来,从C++转换到C#需要再次改变一种思维方式.

Answer 1

您不需要ref在参数声明中使用.对于像你这样的引用类型class A,声明为just的参数A other将导致C#传递对象的引用.

A other在C#中声明的参数与A* otherC++中的类似.

ref A other在C#中声明的参数与A** otherC++中的类似.

class A
{
    int x = 20;

    void Interact(A other)
    {
        if (x % 2 == 0) { other.x++; x /= 2; }
    }

    public void MakeInteraction(A other)
    {
        Interact(other);
        other.Interact(this);
    }

    static void Main()
    {
        A a = new A();
        A b = new A();
        a.MakeInteraction(b);
    }
}