保存到一个int类型的引用 [英] Saving a reference to a int

问题描述

下面是我所试图做的。

static void Main(string[] args)
{
    int test = 0;
    int test2 = 0;
    Test A = new Test(ref test);
    Test B = new Test(ref test);
    Test C = new Test(ref test2);
    A.write(); //Writes 1 should write 1
    B.write(); //Writes 1 should write 2
    C.write(); //Writes 1 should write 1
    Console.ReadLine();
}
class Test
{
    int _a;
    public Test(ref int a)
    {
        _a = a; //I loose the reference here
    }
    public void write()
    {
        var b = System.Threading.Interlocked.Increment(ref _a);
        Console.WriteLine(b);
    }
}

在我真正的代码中，我有一个int值会由多个线程但是当线程称它不会是容易通过它指向它在INT（在这里面发生的真正的代码参数递增的IEnumerator ）。因此，一个要求是引用必须在构造函数中进行。也并非所有的线程将在同一单碱基INT被人指指点点，所以我也不能使用全局静态int值。我知道我可以只框类内部INT和周围传递类，但我想知道这是做这样的事情的正确方法是什么？

In my real code I have a int that will be incremented by many threads however where the threads a called it will not be easy to pass it the parameter that points it at the int(In the real code this is happening inside a IEnumerator). So a requirement is the reference must be made in the constructor. Also not all threads will be pointing at the same single base int so I can not use a global static int either. I know I can just box the int inside a class and pass the class around but I wanted to know if that is the correct way of doing something like this?

我认为可能是正确的方法：

What I think could be the correct way:

static void Main(string[] args)
{
    Holder holder = new Holder(0);
    Holder holder2 = new Holder(0);
    Test A = new Test(holder);
    Test B = new Test(holder);
    Test C = new Test(holder2);
    A.write(); //Writes 1 should write 1
    B.write(); //Writes 2 should write 2
    C.write(); //Writes 1 should write 1
    Console.ReadLine();
}
class Holder
{
    public Holder(int i)
    {
        num = i;
    }
    public int num;
}
class Test
{
    Holder _holder;
    public Test(Holder holder)
    {
        _holder = holder;
    }
    public void write()
    {
        var b = System.Threading.Interlocked.Increment(ref _holder.num);
        Console.WriteLine(b);
    }
}

难道还有比这更好的办法吗？

Is there a better way than this?

推荐答案

基本上，答案是肯定的，你需要一个类。

Basically, the answer is Yes, you need a class.

有是没有的参考诠释'，你可以存储为一个领域的概念。在C＃中也仅限于参数。

There is no concept of 'reference to int' that you can store as a field. In C# it is limited to parameters.

虽然有一个不安全办法（指针为int，为int * ）的处理在该方案中的GC的复杂性使它不切实际和效率低下。

And while there is an unsafe way (pointer to int, int*) the complexities of dealing with the GC in that scenario make it impractical and inefficient.

所以，你的第二个例子看起来不错。

So your second example looks OK.

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