Question

我是新手使用cocos2d-x并且我正在阅读HelloWorldScene.cpp代码文件，到目前为止，除了以下代码行之外，我了解了所有内容：

void HelloWorld::menuCloseCallback(Ref* pSender)
{
Director::getInstance()->end();
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
exit(0);
#endif
}

我的问题如下：CC_TARGET_PLATFORM，CC_PLATFORM_IOS变量有什么作用？，cofigo Director :: getInstance（） - ＆gt; end（）的作用是什么 - ＆gt;结束（）;做什么？函数menuCloseCallback被调用在哪里？

这是代码：

#include "HelloWorldScene.h"
//#include "MainmenuScene.h"

USING_NS_CC; 

Scene* HelloWorld::createScene()
{
// 'scene' is an autorelease object
auto scene = Scene::create();

// 'layer' is an autorelease object
auto layer = HelloWorld::create();

// add layer as a child to scene
scene->addChild(layer);

// return the scene
return scene;
}

// on "init" you need to initialize your instance
bool HelloWorld::init()
{
//////////////////////////////
// 1. super init first
if ( !Layer::init() )
{
    return false;
}

Size visibleSize = Director::getInstance()->getVisibleSize();
Vec2 origin = Director::getInstance()->getVisibleOrigin();

/////////////////////////////
// 2. add a menu item with "X" image, which is clicked to quit the program
//    you may modify it.

// add a "close" icon to exit the progress. it's an autorelease object
auto closeItem = MenuItemImage::create(
                                       "continuar.jpg",
                                       "continuar1.jpg",
                                          CC_CALLBACK_1(HelloWorld::menuCloseCallback, this));

closeItem->setPosition(Vec2(origin.x + visibleSize.width - closeItem->getContentSize().width/2 ,
                            origin.y + closeItem->getContentSize().height/2));

// create menu, it's an autorelease object
auto menu = Menu::create(closeItem, NULL);
menu->setPosition(Vec2::ZERO);
this->addChild(menu, 1);

/*////////////////////////////
// 3. add your codes below...

// add a label shows "Hello World"
// create and initialize a label

auto label = Label::createWithTTF("Hello World", "fonts/Marker Felt.ttf", 24);

// position the label on the center of the screen
label->setPosition(Vec2(origin.x + visibleSize.width/2,
                        origin.y + visibleSize.height - label->getContentSize().height));

// add the label as a child to this layer
this->addChild(label, 1);

// add "HelloWorld" splash screen"
auto sprite = Sprite::create("HelloWorld.png");

// position the sprite on the center of the screen
sprite->setPosition(Vec2(visibleSize.width/2 + origin.x, visibleSize.height/2 + origin.y));

// add the sprite as a child to this layer
this->addChild(sprite, 0);*/

return true;
}


void HelloWorld::menuCloseCallback(Ref* pSender)
{
Director::getInstance()->end();

#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
exit(0);
#endif
}

Answer 1

auto closeItem = MenuItemImage::create(
                                   "continuar.jpg",
                                   "continuar1.jpg",
                                      CC_CALLBACK_1(HelloWorld::menuCloseCallback, this));

MenuItemImage has callbacks ( functions that call's on some event make):

on button pressed but doesn't release finger from pushing - MenuItemImage show continuar1.jpg, in other case it's show continuar.jpg.
on button pressed (on finger push up after pressed it) - it call function HelloWorld::menuCloseCallback with parametr.

Answer 2

代码块

#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
  exit(0);
#endif

检查目标编译平台是否为iOS，如果是，则在exit（0）中添加;

总::的getInstance（） - ＆GT;端（）;

结束当前正在运行的应用程序（关闭 - 这是关闭菜单项所执行的操作）此功能在菜单项create中作为回调连接。

我不明白hello world cocos2d-x的部分代码示例

2 个答案: