鸿蒙ace2.0代码-回调函数-demo示例_鸿蒙共享包 回调

此示例用于展示鸿蒙ace2.0代码中涉及的回调函数，可参照demo示例进行理解

鸿蒙代码示例：

demo示例：

#include<iostream>
#include <functional> 
using CallBack = std::function<void(int32_t)>;
class Event {
public:
	Event(std::string type, int32_t id) : eventType(type), pageId(id){}
	std::string GetEvenType() const
	{
		return eventType;
	}
	int32_t GetPageId() const
	{
		return pageId;
	}
	void SetCallBack(const CallBack& callback) {
		fun = callback;
	}
	CallBack GetCallBack() const {
		return fun;
	}
	void Print(std::string type,int32_t id) const {
		std::cout << "type=" << type.c_str()<<" " << "id=" << id << std::endl;
	}

private:
	std::string eventType;
	int32_t pageId;
	CallBack fun;
};
class AceAsyncEvent {
public:
	AceAsyncEvent() = default;
	static std::function<void(std::string,int32_t) > create(const Event& events)
	{
		return [events](std::string str, int32_t num) {
			events.Print(str,num);
		};
	}
};
int main()
{
	//创建智能指针share_ptr,使其指向Event
	std::shared_ptr<Event> foo=std::make_shared<Event>("touch", 0);
	(*foo).Print("touch", 0);
	std::cout << foo->GetEvenType().c_str() << std::endl;
	std::cout << foo->GetPageId()<< std::endl;

	if (!foo->GetCallBack())
	{
		std::cout << "函数为空" << std::endl;
	}

	//lambda表达式作为参数设置到SetCallBack,此时lambda为回调函数
	foo->SetCallBack([&](int32_t id) {
		std::cout << "函数回调,id="<<id << std::endl;
	});
	auto fun=foo->GetCallBack();
	if (fun) {
		std::cout << "函数不为空" << std::endl;
		//此时执行回调函数，即执行lamda表达式
		fun(32);
	}
	
	auto fun2 = AceAsyncEvent::create(*foo);
	//此处执行回调函数，即执行events.Print(str,num)
	fun2("click", 1);
	return 0;
}
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