如何指定类方法的指针？ （代表？） [英] How to assign pointer to class method? (delegates?)

问题描述

在类Button中：public Widget我有：void（Window :: * OnClick）（）= NULL;

In class Button : public Widget I have: void (Window::*OnClick)() = NULL;

在类Window中是on_click_base（）： 

In class Window is on_click_base(): 

class Window : public Widget
{
public:
    Window(Widget* parent);
    virtual ~Window();
    void show();
    void on_click_base() {}
};

但我更喜欢

but I prefer

class MyWindow : public Window
{
public:
	MyWindow() : Window(nullptr) {}
	void on_click() {
		Dialogs::message_box(L"here click");
	}
};

是错误：

button2.OnClick = window.on_click_base; //非标准语法;使用'&'创建指向成员的指针   

button2.OnClick = window.on_click_base; //non-standard syntax; use '&' to create a pointer to member   

button2.OnClick =& window.on_click_base; //对绑定成员函数表达式的非法操作

button2.OnClick = &window.on_click_base;//illegal operation on bound member function expression

如何做委托之类的事情？

How do anything like delegates?

推荐答案

On 8 / 13/2017 2017年5月33日，AndrzejBorucki写道：

On 8/13/2017 5:33 PM, AndrzejBorucki wrote:

是错误：



button2 .OnClick = window.on_click_base; //非标准语法;使用'&'创建指向成员的指针



button2.OnClick =& window.on_click_base; //对绑定成员函数表达式的非法操作

Are errors:

button2.OnClick = window.on_click_base; //non-standard syntax; use '&' to create a pointer to member

button2.OnClick = &window.on_click_base;//illegal operation on bound member function expression

button2.OnClick =& Window :: on_click_base;

button2.OnClick = &Window::on_click_base;

请注意，像OnClick这样的指向成员的指针仅指成员函数，但是不是要调用它的对象。需要单独存储指向所述对象的指针或引用。

Note that pointer-to-member like your OnClick only refers to a member function, but not to an object on which to call it. A pointer or reference to said object would need to be stored separately.

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