精灵随手指移动，你点哪我走哪！

林炳文Evankaka原创作品。转载请注明出处

本文要实现飞机游戏中，人的手指按着飞机，就能拖着飞机走动，这里实现了当你手指按在手机的图片上，手指一直按着屏幕，飞机就会跟着你走。同时，还加入了边界判断条件，让飞机在你的视野内移动，实现的效果完全和我们手机上的飞机游戏一样。

效果：

一、代码编写

1、头文件GameMain.h

/****@作者 林炳文（邮箱：ling20081005@126.com）*@博客 *@时间 2015.3.8*@功能 游戏的主界面*/#ifndef __GameMain_H__#define __GameMain_H__#include "BackLayerDown.h"#include "BackLayerUp.h"#include "cocos2d.h"USING_NS_CC;class GameMain : public cocos2d::Layer{public:static cocos2d::Scene* createScene();virtual bool init();virtual bool onTouchBegan(cocos2d::Touch *touch, cocos2d::Event *unused_event);virtual void onTouchMoved(cocos2d::Touch *touch, cocos2d::Event *unused_event);virtual void onTouchEened(cocos2d::Touch *touch, cocos2d::Event *unused_event);virtual void onTouchCancelled(cocos2d::Touch *touch, cocos2d::Event *unused_even);CREATE_FUNC(GameMain);private:bool isHeroPlaneControl;//飞机是否被控制着float mDeltaX;//英雄飞机随手指移动时的X偏移量float mDeltaY;//英雄飞机随手指移动时的Y偏移量Sprite *mHeroPlane;//英雄飞机};#endif // __GameMain_H__然后在GameMain.cpp中增加：#include "GameMain.h"USING_NS_CC;Scene* GameMain::createScene(){auto scene = Scene::create();auto layer = GameMain::create();scene->addChild(layer);return scene;}bool GameMain::init(){Size visibleSize = Director::getInstance()->getVisibleSize();Point origin = Director::getInstance()->getVisibleOrigin();//这是地面图层this->addChild(BackLayerUp::create());//这是白云图层this->addChild(BackLayerDown::create());//加个飞机mHeroPlane = Sprite::create("air1.png");mHeroPlane->setPosition(Vec2(visibleSize.width / 2, visibleSize.height / 5));this->addChild(mHeroPlane, 1, 100);isHeroPlaneControl = false;//打开触摸，增加触摸监听事件this->setTouchEnabled(true);auto listen = EventListenerTouchOneByOne::create();listen->onTouchBegan = CC_CALLBACK_2( GameMain::onTouchBegan,this);listen->onTouchMoved = CC_CALLBACK_2(GameMain::onTouchMoved, this);listen->onTouchEnded = CC_CALLBACK_2(GameMain::onTouchEened, this);listen->onTouchCancelled = CC_CALLBACK_2(GameMain::onTouchCancelled, this);listen->setSwallowTouches(false);//不截取触摸事件Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listen,this);return true;}bool GameMain::onTouchBegan(cocos2d::Touch *touch, cocos2d::Event *unused_event){Point mHeroPos = mHeroPlane->getPosition();Point mBeganPos = touch->getLocationInView();mBeganPos = Director::getInstance()->convertToGL(mBeganPos);//判断当前手指按下区域是否是英雄飞机的区域,并且计算飞机要移动时的偏移量if (mBeganPos.x > mHeroPos.x – mHeroPlane->getContentSize().width / 2 && mBeganPos.x<mHeroPos.x + mHeroPlane->getContentSize().width / 2 &&mBeganPos.y>mHeroPos.y – mHeroPlane->getContentSize().height / 2 && mBeganPos.y < mHeroPos.y + mHeroPlane->getContentSize().height / 2){isHeroPlaneControl = true;//計算偏移量mDeltaX = mBeganPos.x – mHeroPos.x;mDeltaY = mBeganPos.y – mHeroPos.y;}return true;}void GameMain::onTouchMoved(cocos2d::Touch *touch, cocos2d::Event *unused_event){if (isHeroPlaneControl){Point mMovedPos = touch->getLocationInView();mMovedPos = Director::getInstance()->convertToGL(mMovedPos);Size visibleSize = Director::getInstance()->getVisibleSize();Point origin = Director::getInstance()->getVisibleOrigin();float x = mMovedPos.x – mDeltaX;//記得減去偏移量float y = mMovedPos.y – mDeltaY;if (x <= mHeroPlane->getContentSize().width / 2 + origin.x)//x到达屏幕左边界x = mHeroPlane->getContentSize().width / 2 + origin.x;else if (x >= visibleSize.width – mHeroPlane->getContentSize().width / 2)//x到达屏幕右边界x = visibleSize.width – mHeroPlane->getContentSize().width / 2;if (y <= mHeroPlane->getContentSize().height / 2 + origin.y)//y到达屏幕下边界y = mHeroPlane->getContentSize().height / 2 + origin.y;else if (y >= visibleSize.height – mHeroPlane->getContentSize().height / 2)//x到达屏幕上边界y = visibleSize.height – mHeroPlane->getContentSize().height/ 2;//飞机跟随手指移动mHeroPlane->setPosition(Vec2(x,y));}}void GameMain::onTouchEened(cocos2d::Touch *touch, cocos2d::Event *unused_event){isHeroPlaneControl = false;}void GameMain::onTouchCancelled(cocos2d::Touch *touch, cocos2d::Event *unused_even){isHeroPlaneControl = false;}

这里再说一写主要函数：

头文件增加触摸事件：

virtual bool onTouchBegan(cocos2d::Touch *touch, cocos2d::Event *unused_event);virtual void onTouchMoved(cocos2d::Touch *touch, cocos2d::Event *unused_event);virtual void onTouchEened(cocos2d::Touch *touch, cocos2d::Event *unused_event);virtual void onTouchCancelled(cocos2d::Touch *touch, cocos2d::Event *unused_even);实现文件开启触摸事件监听：//打开触摸，增加触摸监听事件this->setTouchEnabled(true);auto listen = EventListenerTouchOneByOne::create();listen->onTouchBegan = CC_CALLBACK_2( GameMain::onTouchBegan,this);listen->onTouchMoved = CC_CALLBACK_2(GameMain::onTouchMoved, this);listen->onTouchEnded = CC_CALLBACK_2(GameMain::onTouchEened, this);listen->onTouchCancelled = CC_CALLBACK_2(GameMain::onTouchCancelled, this);listen->setSwallowTouches(false);//不截取触摸事件Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listen,this);然后就是触摸事件 的处理了：bool GameMain::onTouchBegan(cocos2d::Touch *touch, cocos2d::Event *unused_event){Point mHeroPos = mHeroPlane->getPosition();Point mBeganPos = touch->getLocationInView();mBeganPos = Director::getInstance()->convertToGL(mBeganPos);//判断当前手指按下区域是否是英雄飞机的区域,并且计算飞机要移动时的偏移量if (mBeganPos.x > mHeroPos.x – mHeroPlane->getContentSize().width / 2 && mBeganPos.x<mHeroPos.x + mHeroPlane->getContentSize().width / 2 &&mBeganPos.y>mHeroPos.y – mHeroPlane->getContentSize().height / 2 && mBeganPos.y < mHeroPos.y + mHeroPlane->getContentSize().height / 2){isHeroPlaneControl = true;//計算偏移量mDeltaX = mBeganPos.x – mHeroPos.x;mDeltaY = mBeganPos.y – mHeroPos.y;}return true;}void GameMain::onTouchMoved(cocos2d::Touch *touch, cocos2d::Event *unused_event){if (isHeroPlaneControl){Point mMovedPos = touch->getLocationInView();mMovedPos = Director::getInstance()->convertToGL(mMovedPos);Size visibleSize = Director::getInstance()->getVisibleSize();Point origin = Director::getInstance()->getVisibleOrigin();float x = mMovedPos.x – mDeltaX;//記得減去偏移量float y = mMovedPos.y – mDeltaY;if (x <= mHeroPlane->getContentSize().width / 2 + origin.x)//x到达屏幕左边界x = mHeroPlane->getContentSize().width / 2 + origin.x;else if (x >= visibleSize.width – mHeroPlane->getContentSize().width / 2)//x到达屏幕右边界x = visibleSize.width – mHeroPlane->getContentSize().width / 2;if (y <= mHeroPlane->getContentSize().height / 2 + origin.y)//y到达屏幕下边界y = mHeroPlane->getContentSize().height / 2 + origin.y;else if (y >= visibleSize.height – mHeroPlane->getContentSize().height / 2)//x到达屏幕上边界y = visibleSize.height – mHeroPlane->getContentSize().height/ 2;//飞机跟随手指移动mHeroPlane->setPosition(Vec2(x,y));}}void GameMain::onTouchEened(cocos2d::Touch *touch, cocos2d::Event *unused_event){isHeroPlaneControl = false;}void GameMain::onTouchCancelled(cocos2d::Touch *touch, cocos2d::Event *unused_even){isHeroPlaneControl = false;} 方法很简单，代码量也很少，有需要的把上面的自己拿过去，把图片改改，把类名改改就可以了。让我们将事前的忧虑，换为事前的思考和计划吧!