cocos2dx 官方示例学习（一）, 了解demo结构

如果你是cocos2dx beta 版的, 官方给的demo就在 cocos2d-x-3.0beta\build 中

打开cocos2d-win32.vc2012.sln

找到TextCpp项目 展开Classes

该TextCpp分2场景， 第一个场景就是主界面 要你选择测试的案例， 第二个场景就是测试案例的界面

AppDelegate 程序就是从这里开始的

controller 这就是程序的第一个场景， 即主界面

testBasic 这是第二个场景的基类，所有的测试案例界面都是基于这个场景的子类场景

BaseTest 这是第二个场景中的层的基类，所有的测试案例界场景都会调用基于这个层的子类层

tests.h 这是资源地址

VisibleRect 是用来方便设置坐标的类

我们先来看下AppDelegate.cpp中的代码

//找到下面这段上面的都先不管    auto scene = Scene::create();//创建一个场景    auto layer = new TestController();//创建一个层    layer->autorelease();//放入自动回收池中    scene->addChild(layer);//把层放入场景中    director->runWithScene(scene);//跑该场景

然后找到主界面类controller.h

#ifndef _CONTROLLER_H_#define _CONTROLLER_H_#include "cocos2d.h"USING_NS_CC;class TestController : public Layer{public:    TestController();    ~TestController();//菜单回调函数    void menuCallback(Object * sender);//关闭按钮回调函数    void closeCallback(Object * sender);//触摸开始回调函数    bool onTouchBegan(Touch* touches, Event  *event);//触摸移动回调函数    void onTouchMoved(Touch* touches, Event  *event);//鼠标滚动回调函数    void onMouseScroll(Event *event);private:    Point _beginPos;    Menu* _itemMenu;};#endif

看看如何初始化该类的

TestController::TestController(): _beginPos(Point::ZERO){    // add close menu    auto closeItem = MenuItemImage::create(s_pathClose/*正常的图片*/, s_pathClose/*按下去的图片*/, CC_CALLBACK_1(TestController::closeCallback, this)/*触发的函数*/ );    auto menu =Menu::create(closeItem, NULL);//好似一个MenuItemImage集合    menu->setPosition( Point::ZERO );    closeItem->setPosition(Point( /*自定义的窗口类*/VisibleRect::right().x - 30, VisibleRect::top().y - 30));    // add menu items for tests 添加文字项菜单 用于测试    _itemMenu = Menu::create();    for (int i = 0; i < g_testCount; ++i)    {// #if (CC_TARGET_PLATFORM == CC_PLATFORM_MARMALADE)//         auto label = LabelBMFont::create(g_aTestNames[i].c_str(),  "fonts/arial16.fnt");// #else        auto label = LabelTTF::create( g_aTestNames[i].test_name, "Arial", 24);// #endif                auto menuItem = MenuItemLabel::create(label, CC_CALLBACK_1(TestController::menuCallback, this));        _itemMenu->addChild(menuItem, i + 10000);        menuItem->setPosition( Point( VisibleRect::center().x, (VisibleRect::top().y - (i + 1) * LINE_SPACE) ));    }//设置itemMenu容器的大小 以便于拉动    _itemMenu->setContentSize(Size(VisibleRect::getVisibleRect().size.width, (g_testCount + 1) * (LINE_SPACE)));    _itemMenu->setPosition(s_tCurPos);    addChild(_itemMenu);    addChild(menu, 1);    // Register Touch Event 注册触摸监听事件    auto listener = EventListenerTouchOneByOne::create();    listener->setSwallowTouches(true);    //回调函数    listener->onTouchBegan = CC_CALLBACK_2(TestController::onTouchBegan, this);    listener->onTouchMoved = CC_CALLBACK_2(TestController::onTouchMoved, this);        _eventDispatcher->addEventListenerWithSceneGraphPriority(listener, this);//鼠标滚动事件    auto mouseListener = EventListenerMouse::create();    mouseListener->onMouseScroll = CC_CALLBACK_1(TestController::onMouseScroll, this);    _eventDispatcher->addEventListenerWithSceneGraphPriority(mouseListener, this);}TestController::~TestController(){}void TestController::menuCallback(Object * sender){//净化缓存, 包括纹理缓存, 精灵缓存和字体缓存Director::getInstance()->purgeCachedData();    // get the userdata, it's the index of the menu item clicked//传进来的 sender 为点击的Menuitem    auto menuItem = static_cast<MenuItem *>(sender);    int idx = menuItem->getZOrder() - 10000;    // create the test scene and run it//创建场景    auto scene = g_aTestNames[idx].callback();    if (scene)    {//运行场景        scene->runThisTest();        scene->release();    }}

testBasic基类的主要功能就是创建一个返回的按钮

void TestScene::onEnter(){    Scene::onEnter();    //add the menu item for back to main menu//#if (CC_TARGET_PLATFORM == CC_PLATFORM_MARMALADE)//    auto label = LabelBMFont::create("MainMenu",  "fonts/arial16.fnt");//#else//返回按钮    auto label = LabelTTF::create("MainMenu", "Arial", 20);//#endif    auto menuItem = MenuItemLabel::create(label, testScene_callback );    auto menu = Menu::create(menuItem, NULL);    menu->setPosition( Point::ZERO );    menuItem->setPosition( Point( VisibleRect::right().x - 50, VisibleRect::bottom().y + 25) );    addChild(menu, 1);}

让我们看看BaseTest都做了什么

////  BaseTest.h//  TestCpp////  Created by Ricardo Quesada on 6/6/13.////#ifndef __TestCpp__BaseTest__#define __TestCpp__BaseTest__#include "cocos2d.h"class BaseTest : public cocos2d::Layer{public://标题    virtual std::string title() const;//副标题    virtual std::string subtitle() const;//重新开始virtual void restartCallback(Object* sender);//下一个virtual void nextCallback(Object* sender);//上一个virtual void backCallback(Object* sender);//进入    virtual void onEnter() override;//退出    virtual void onExit() override;};#endif /* defined(__TestCpp__BaseTest__) */

////  BaseTest.cpp//  TestCpp////  Created by Ricardo Quesada on 6/6/13.////#include "BaseTest.h"#include "VisibleRect.h"#include "testResource.h"USING_NS_CC;void BaseTest::onEnter(){Layer::onEnter();// add title and subtitle 创建标题    std::string str = title();    const char * pTitle = str.c_str();    auto label = LabelTTF::create(pTitle, "Arial", 32);    addChild(label, 9999);    label->setPosition( Point(VisibleRect::center().x, VisibleRect::top().y - 30) );    std::string strSubtitle = subtitle();    if( ! strSubtitle.empty() )    {        auto l = LabelTTF::create(strSubtitle.c_str(), "Thonburi", 16);        addChild(l, 9999);        l->setPosition( Point(VisibleRect::center().x, VisibleRect::top().y - 60) );    }    // add menu 创建几个按钮// CC_CALLBACK_1 == std::bind( function_ptr, instance, std::placeholders::_1, ...)    auto item1 = MenuItemImage::create(s_pathB1, s_pathB2, CC_CALLBACK_1(BaseTest::backCallback, this) );    auto item2 = MenuItemImage::create(s_pathR1, s_pathR2, CC_CALLBACK_1(BaseTest::restartCallback, this) );    auto item3 = MenuItemImage::create(s_pathF1, s_pathF2, CC_CALLBACK_1(BaseTest::nextCallback, this) );    auto menu = Menu::create(item1, item2, item3, NULL);    menu->setPosition(Point::ZERO);    item1->setPosition(Point(VisibleRect::center().x - item2->getContentSize().width*2, VisibleRect::bottom().y+item2->getContentSize().height/2));    item2->setPosition(Point(VisibleRect::center().x, VisibleRect::bottom().y+item2->getContentSize().height/2));    item3->setPosition(Point(VisibleRect::center().x + item2->getContentSize().width*2, VisibleRect::bottom().y+item2->getContentSize().height/2));    addChild(menu, 9999);}void BaseTest::onExit(){Layer::onExit();}//等待重写std::string BaseTest::title() const{return "";}//等待重写std::string BaseTest::subtitle() const{return "";}//等待重写void BaseTest::restartCallback(Object* sender){log("override restart!");}//等待重写void BaseTest::nextCallback(Object* sender){log("override next!");}//等待重写void BaseTest::backCallback(Object* sender){log("override back!");}

这是测试层的基类，所以有很多函数定义需要之后补充

我们随便打开一个测试类比如UnitTest.h

#ifndef __UNIT_TEST__#define __UNIT_TEST__#include "../testBasic.h"#include "../BaseTest.h"class UnitTestScene : public TestScene{public:    virtual void runThisTest() override;};class UnitTestDemo : public BaseTest{public:    virtual void onEnter() override;    virtual void onExit() override;    virtual std::string title() const override;    virtual std::string subtitle() const override;    virtual void restartCallback(Object* sender) override;    virtual void nextCallback(Object* sender) override;    virtual void backCallback(Object* sender) override;};//-------------------------------------class TemplateVectorTest : public UnitTestDemo{public:    CREATE_FUNC(TemplateVectorTest);    virtual void onEnter() override;    virtual std::string subtitle() const override;    void constFunc(const Vector<Node*>& vec) const;};class TemplateMapTest : public UnitTestDemo{public:    CREATE_FUNC(TemplateMapTest);    virtual void onEnter() override;    virtual std::string subtitle() const override;    void constFunc(const Map<std::string, Node*>& map) const;};class ValueTest : public UnitTestDemo{public:    CREATE_FUNC(ValueTest);    virtual void onEnter() override;    virtual std::string subtitle() const override;    void constFunc(const Value& value) const;};#endif /* __UNIT_TEST__ */

该类的场景继承基类场景，层继承基类的层 并重写了基类层的函数

而这些测试类在哪里被调用呢  是在controller类中

struct {//名字const char *test_name;//场景指针std::function<TestScene*()> callback;} g_aTestNames[] = {    //    // TESTS MUST BE ORDERED ALPHABETICALLY    //     violators will be prosecuted    //    { "AUnitTest", []() { return new UnitTestScene(); }},    { "ANewRenderTest", []() { return new NewRendererTestScene(); } },{ "Accelerometer", []() { return new AccelerometerTestScene(); } },{ "ActionManagerTest", [](){return new ActionManagerTestScene(); } },{ "ActionsEaseTest", [](){return new ActionsEaseTestScene();} },{ "ActionsProgressTest", [](){return new ProgressActionsTestScene(); } },{ "ActionsTest", [](){ return new ActionsTestScene(); } },{ "Box2dTest", []() { return new Box2DTestScene(); } },{ "Box2dTestBed", []() { return new Box2dTestBedScene(); } },{ "BugsTest", []() { return new BugsTestScene(); } },#if (CC_TARGET_PLATFORM != CC_PLATFORM_MARMALADE){ "ChipmunkTest", []() { return new ChipmunkAccelTouchTestScene(); } },#endif{ "ClickAndMoveTest", [](){return new ClickAndMoveTestScene(); } },#if (CC_TARGET_PLATFORM != CC_PLATFORM_MARMALADE){ "ClippingNodeTest", []() { return new ClippingNodeTestScene(); } },#endif{ "CocosDenshionTest", []() { return new CocosDenshionTestScene(); } },{ "ConfigurationTest", []() { return new ConfigurationTestScene(); } },{ "ConsoleTest", []() { return new ConsoleTestScene(); } },#if (CC_TARGET_PLATFORM != CC_PLATFORM_EMSCRIPTEN)#if (CC_TARGET_PLATFORM != CC_PLATFORM_NACL)#if (CC_TARGET_PLATFORM != CC_PLATFORM_MARMALADE)#if (CC_TARGET_PLATFORM != CC_PLATFORM_BADA){ "CurlTest", []() { return new CurlTestScene(); } },#endif#endif#endif#endif{ "CurrentLanguageTest", []() { return new CurrentLanguageTestScene(); } },{ "DrawPrimitivesTest", [](){return new DrawPrimitivesTestScene();} },    { "EventDispatcherTest(NEW)", []() { return new EventDispatcherTestScene(); } },{ "EffectAdvancedTest", []() { return new EffectAdvanceScene(); } },{ "EffectsTest", [](){return new EffectTestScene();} },{ "ExtensionsTest", []() { return new ExtensionsTestScene(); } },{ "FileUtilsTest", []() { return new FileUtilsTestScene(); } },{ "FontTest", []() { return new FontTestScene(); } },{ "IntervalTest", [](){return new IntervalTestScene(); } },{ "KeyboardTest", []() { return new KeyboardTestScene(); } },#if (CC_TARGET_PLATFORM != CC_PLATFORM_BADA){ "KeypadTest", []() { return new KeypadTestScene(); } },#endif{ "LabelTest", [](){return new AtlasTestScene(); } },    { "LabelTestNew", [](){return new AtlasTestSceneNew(); } },{ "LayerTest", [](){return new LayerTestScene();} },{ "MenuTest", [](){return new MenuTestScene();} },{ "MotionStreakTest", [](){return new MotionStreakTestScene();} },    { "MouseTest", []() { return new MouseTestScene(); } },{ "MutiTouchTest", []() { return new MutiTouchTestScene(); } },{ "NodeTest", [](){return new CocosNodeTestScene();} },{ "ParallaxTest", [](){return new ParallaxTestScene(); } },{ "ParticleTest", [](){return new ParticleTestScene(); } },{ "PerformanceTest", []() { return new PerformanceTestScene(); } },{ "PhysicsTest", []() { return new PhysicsTestScene(); } },{ "RenderTextureTest", [](){return new RenderTextureScene(); } },{ "RotateWorldTest", [](){return new RotateWorldTestScene(); } },{ "SceneTest", [](){return new SceneTestScene();} },{ "SchedulerTest", [](){return new SchedulerTestScene(); } },{ "ShaderTest", []() { return new ShaderTestScene(); } },    { "ShaderTestSprite", []() { return new ShaderTestScene2(); } },{ "SpineTest", []() { return new SpineTestScene(); } },{ "SpriteTest", [](){return new SpriteTestScene(); } },{ "TextInputTest", [](){return new TextInputTestScene(); } },{ "Texture2DTest", [](){return new TextureTestScene(); } },#if (CC_TARGET_PLATFORM != CC_PLATFORM_MARMALADE){ "TextureCacheTest", []() { return new TextureCacheTestScene(); } },#endif{ "TexturePackerEncryption", []() { return new TextureAtlasEncryptionTestScene(); } },{ "TileMapTest", [](){return new TileMapTestScene(); } },{ "TouchesTest", [](){return new PongScene();} },{ "TransitionsTest", [](){return new TransitionsTestScene();} },{ "UserDefaultTest", []() { return new UserDefaultTestScene(); } },{ "ZwoptexTest", []() { return new ZwoptexTestScene(); } },};