用void类型定义类属性（不是方法）

Question

I'm trying to build a class called GameObject (for consoleApplication game), and that GameObject should have a function "onFrame" that is called, let's say, every 0.1 seconds.

But the catch is, that this function (void) should be unique for every gameObject - let's say I have GameObject: G1, G2. G1 will increase a variable by 1 in it's onFrame, and G2 will print something to the console (just examples).

Is it possible to do that?

I tried doing that in this way:

class GameObject 
{
    public void onFrame;

    public GameObject (void of) //constructor
    {
        onFrame = of;
        Thread t = new Thread(runOnFrame);
        t.isBackgroundThread = true;
        t.Start();
    }

    protected void runOnFrame () 
    {
        while (true)
        {
            Thread.Sleep(100);
            if (onFrame != null) onFrame(); //EDIT: that (0) was typed by mistake
        }
    }
}

And the main function:

public static int i = 0;
static void Main (string[] args)
{
    GameObject G1 = new GameObject(new void (){
        i++;
    });
    GameObject G2 = new GameObject(new void () {
        Console.WriteLine("OnFrame is being called!");
    })
}

But it doesn't seem like being the right way to do that... Is it possible? And how do I do that?

Answer 1

What you're looking for is an Action , which is the same as a void delegate:

class GameObject 
{
    public Action onFrame;

    public GameObject (Action of) //constructor
    {
        onFrame = of;
        Thread t = new Thread(runOnFrame);
        t.isBackgroundThread = true;
        t.Start();
    }

    protected void runOnFrame () 
    {
        while (true)
        {
            Thread.Sleep(100);
            if (onFrame != null) onFrame();
        }
    }
}

However I would suggest using a Timer instead of calling thread.Sleep in a continuous loop.

One way to pass in a delegate is to use lambda syntax:

GameObject G1 = new GameObject(() => i++ );

The () is a placeholder for an empty input parameter set:

Answer 2

What you need is a delegate.

Your "onFrame" definition should look something like this:

public delegate void SimpleDelegate();
public SimpleDelegate onFrame;

Your constructor would become this:

public GameObject (SimpleDelegate of)
{
    onFrame = of;
    Thread t = new Thread(runOnFrame);
    t.isBackgroundThread = true;
    t.Start();
}

Then later, something like this:

GameObject G1 = new GameObject(new SimpleDelegate(() => {
    i++;
}));

.....