在D到C函数中，类方法回调。-ClassmethodcallbacksinDtoCfunctions

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The way I'd do it is to have a static map of the pointers to the class, so like:

我这样做的方法是有一个指向类的指针的静态映射，比如:

static YourWindowClass[GLFWwindow*] mappings;

Then, in the constructor, once you get a GLFWwindow pointer, add it right in:

然后，在构造函数中，一旦获得了一个GLFWwindow指针，就将它添加到:

mappings[m_Window.window] = this;

Now, make the static extern(C) function to use as the callback. When it gets a pointer from C, look up your class reference in that mappings array and then go ahead and call the member function through that, forwarding the arguments.

现在，让静态外部(C)函数用作回调函数。当它从C获取一个指针时，在那个映射数组中查找你的类引用，然后通过它调用成员函数，转发参数。

So a bit of an extra step, but since it doesn't look like the callback lets you pass user-defined data to it (BTW, attention all lib writers: user-defined void* to the callbacks is sooooo useful, you should do it whenever possible!), but since it doesn't do that the associative array is the next best thing.

所以一个额外的步骤,但是因为它看起来不像它的回调函数可以通过用户定义的数据(顺便说一句,所有自由作家注意:用户定义的回调函数void *是如此的有用,你应该尽可能地做到!),但由于没有关联数组是再好不过的事情了。

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Well, I have figured it out my own. The solution I went with was a Singleton class InputManager. Instances of RenderWindow attach themselves to it with the following function. The InputManager then creates an anonymous function() for the RenderWindow that receives events, which then calls a function that handles the actual event.

嗯，我自己也算出来了。我使用的解决方案是一个独立类InputManager。RenderWindow的实例与下面的函数连接在一起。然后InputManager为接收事件的RenderWindow创建一个匿名函数()，然后调用一个处理实际事件的函数。

The idea is then that listeners attach themselves to the InputManager and receive keyboard events for the RenderWindow they requested.

然后，侦听器将自己连接到InputManager并接收他们请求的RenderWindow的键盘事件。

class InputManager {
    private static InputManager m_Instance;
    private RenderWindow[] m_Watched;
    private KeyboardListener[][RenderWindow] m_KeyListeners;

    public void recvKeyEvent(GLFWwindow* w, int k, int c, int a, int m) {
        writeln("Received key: ", k);
    }

    public void watch(RenderWindow win) {
        if (!isWatched(win)) {
            // Relay the key callbacks onto the InputManager.
            GLFWkeyfun keyCB = function(GLFWwindow* w, int k, int c, int a, int m) {
                InputManager().recvKeyEvent(w, k, c, a, m);
            };
            glfwSetKeyCallback(win.window, keyCB);
        }
    }

    private bool isWatched(RenderWindow win) {
        foreach(RenderWindow w; m_Watched) {
            if (win == w) {
                return true;
            }
        }

        return false;
    }

    public static InputManager opCall() {
        if (m_Instance is null) {
            m_Instance = new InputManager();
        }

        return m_Instance;
    }

    private this() {
        // nothing
    }
}

Works like a charm, now to figure out how to properly attach listeners elegantly.

像符咒一样工作，现在想办法正确地连接听众。

For those curious, the full source code with how this is set up can be found at https://github.com/Adel92/Mage2D. I hope it helps someone else in a similar position with callbacks.

对于那些好奇的人，可以在https://github.com/Adel92/Mage2D中找到完整的源代码。我希望它能帮助其他人在类似的岗位上有回调。