Cocos2d x UI development CCControlSlider control class use instance

See article: (link: #) for some configuration when controls are used. Here just write out the source code, inside the comments on the use of the control has a detailed introduction.

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

		//Sets a label that displays a string
		CCLabelTTF * title = CCLabelTTF::create("slider value = 0.00","Arial",32);
		title->setPosition(ccp(240,200));
		//Set the tag of the label to 1 for easy retrieval later
		this->addChild(title,0,1);

		//These three pictures are the bottom, the progress bar, and the control button
		CCControlSlider * slider = CCControlSlider::create("sliderTrack.png","sliderProgress.png",
			"sliderThumb.png");

		//Set the maximum and minimum values for the slider
		slider->setMaximumValue(100);
		slider->setMinimumValue(0);
		//Adds an event listener function to the slider
		slider->addTargetWithActionForControlEvents(this,cccontrol_selector(HelloWorld::valueChanged),
			CCControlEventValueChanged);
		//Set the location
		slider->setPosition(ccp(240,160));
		this->addChild(slider);

		//Using the CCControlSlider to implement the health bar, simply change the third control button to be transparent and it will look like a health bar
		CCControlSlider * slider2 = CCControlSlider::create("sliderTrack.png","progress.png","sliderThumb2.png");
		//Make it impossible to change its value by the following function
		slider2->setTouchEnabled(false);
		slider2->setMaximumValue(100);
		slider2->setMinimumValue(0);
		//You can add an event handler and change its value in the event handler
		slider2->setValue(100);
		slider2->setPosition(ccp(240,100));
		this->addChild(slider2);

    bRet = true;
  } while (0);

  return bRet;
}

//Notice that this function needs to pass in two parameter types
void HelloWorld::valueChanged(CCObject * pSender,CCControlEvent controlEvent)
 {
	CCControlSlider * slider = (CCControlSlider *)pSender;
	CCLabelTTF * title = (CCLabelTTF *)this->getChildByTag(1);
	//Try not to change the content of CCLabelTTF when using it, for the sake of simplicity
	title->setString(CCString::createWithFormat("slider value = %0.02f",slider->getValue())->getCString());
 }