bool HelloWorld::init()
{
 bool bRet = false;
 do
 {
  CC_BREAK_IF(!CCLayer::init());

  //CCControlPotentiometer参数是底座，进度条，控制按钮图片资源
  CCControlPotentiometer * potentiometer = CCControlPotentiometer::create("potentiometerTrack.png",
   "potentiometerProgress.png","potentiometerButton.png");
  //设置最大值和最小值以及初值
  potentiometer->setMaximumValue(100.0);
  potentiometer->setMinimumValue(0.0);
  potentiometer->setValue(50);

  potentiometer->setPosition(ccp(240,160));
  this->addChild(potentiometer);

  //添加事件监听
  potentiometer->addTargetWithActionForControlEvents(this,cccontrol_selector(HelloWorld::valueChanged),
   CCControlEventValueChanged);

  bRet = true;
 }
 while(0);

 return bRet;
}

void HelloWorld::valueChanged(CCObject * pSender,CCControlEvent controlEvent)
{
 CCControlPotentiometer * potentiometer = (CCControlPotentiometer *)pSender;
 CCString * string = CCString::createWithFormat("%f",potentiometer->getValue());
 CCLog(string->getCString());
}