#ifndef _CONTROL_H_
#define _CONTROL_H_
#include "cocos2d.h"
USING_NS_CC;
class Control : public cocos2d::CCLayer
{
public:
	virtual bool init();
	CREATE_FUNC(Control);
	virtual void onEnter();
	virtual void onExit();
	virtual bool ccTouchBegan(CCTouch* touch,CCEvent* event);
    virtual void ccTouchMoved(CCTouch* touch,CCEvent* event);
    virtual void ccTouchEnded(CCTouch* touch,CCEvent* event);
private:
	CCSize visibleSize; //可视窗口大小
	CCSprite* control_bg;
	CCSprite* cen;
	void initData();
	bool isOnControl;
	CCPoint origin; //摇杆中心点
	float r_control;
};
#endif

Control.cpp

#include"Control.h"
USING_NS_CC;
bool Control::init()
{
	if (!CCLayer::init())
	{
		return false;
	}
	initData();
	return true;
}
void Control::initData()
{
	origin = ccp(150,150);  //摇杆原点	
	control_bg = CCSprite::create("dpadUp.png");
	control_bg->setPosition(origin);
	control_bg->setScale(2);
	this->addChild(control_bg);
	cen = CCSprite::create("joystickUp.png");
	cen->setPosition(origin);
	this->addChild(cen);
	CCRect r = control_bg->boundingBox();
	r_control = (r.getMaxX()-r.getMinX())/2; //摇杆半径
}
void Control::onEnter()
{
	CCLayer::onEnter();
	CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this,false);
}
bool Control::ccTouchBegan(CCTouch* touch,CCEvent* event)
{
	if (cen->boundingBox().containsPoint(touch->getLocation()))
	{
		isOnControl = true;
		cen->setScale(1.1);
	}
	return true;
}
void Control::ccTouchMoved(CCTouch* touch,CCEvent* event)
{
	if (isOnControl)  
	{
		CCPoint p_touch = touch->getLocation();
		float distance = sqrt((p_touch.x - origin.x)*(p_touch.x - origin.x)+(p_touch.y - origin.y)*(p_touch.y - origin.y)); //触摸点和摇杆起点的距离
		if (distance <= r_control)
		{
			cen->setPosition(touch->getLocation());
			cen->setScale(1.1);
		}
		else
		{
			float x = r_control/distance * (p_touch.x - origin.x)+origin.x;
			float y = r_control/distance * (p_touch.y - origin.y)+origin.y;
			cen->setPosition(ccp(x,y));
			cen->setScale(1.1);
		}
	}
	else
	{
		//do nothing
	}
}
void Control::ccTouchEnded(CCTouch* touch,CCEvent* event)
{
	isOnControl = false;
	cen->setPosition(origin);
	cen->setScale(1);
}
void Control::onExit()
{
	CCDirector::sharedDirector()->getTouchDispatcher()->removeAllDelegates();
	CCLayer::onExit();
}

在场景中使用：

control = Control::create();
	this->addChild(control,1);

代码和素材下载地址: