Cocos2dx实现跳动的数字效果

封装的类如下：

.h文件

class DigitalBeatText:public cocos2d::Node
{
public:
    DigitalBeatText();
    ~DigitalBeatText();
    static DigitalBeatText *create(int value);

    void setValue(int newValue);
protected:
    bool init(int value);

    void setValueNoAction(int newValue);
    void startRoll();
    void stopRoll();
	
    void onTimeHandler(float dt);
protected:
    cocos2d::ui::Text * m_txt;
    int					m_lastValue;
    int					m_newValue;
    int					m_valueGap;        //数字跳动间隔
    float               m_scheduleInterval;//调度器间隔
    bool                m_isReverse;       // true: 从大到小
};

.cpp文件：

DigitalBeatText::DigitalBeatText() 
:m_txt(nullptr)
, m_lastValue(0)
, m_newValue(0)
, m_valueGap(0)
, m_scheduleInterval(1.0f/60.f)
, m_isReverse(false)
{

}

DigitalBeatText::~DigitalBeatText()
{
}

DigitalBeatText* DigitalBeatText::create(int value)
{
    auto pRet = new DigitalBeatText;
    if (pRet->init(value))
    {
        pRet->autorelease();
        return pRet;
    }
    CC_SAFE_DELETE(pRet);
    return nullptr;
}

bool DigitalBeatText::init(int value)
{
    if (!Node::init()){
        return false;
    }
    char buff[16] = { 0 };
    m_txt = ui::Text::create();
    m_txt->setFontSize(36);
    sprintf(buff, "%d", value);
    m_txt->setString(buff);
    this->addChild(m_txt);
    return true;
}

void DigitalBeatText::setValue(int newValue)
{
    m_isReverse = newValue < m_lastValue;
    stopRoll();
    m_newValue = newValue;
    startRoll();
}

void DigitalBeatText::setValueNoAction(int newValue)
{
    m_lastValue = newValue;
    m_newValue = newValue;
    m_txt->setString(cocos2d::StringUtils::toString(m_lastValue));
}

void DigitalBeatText::startRoll()
{
    int count = m_newValue - m_lastValue;
    if (count>0){
        m_valueGap = ceil(count / (1.0 / m_scheduleInterval));
    }else{
        m_valueGap = floor(count / (1.0 / m_scheduleInterval));
    }
    schedule(CC_SCHEDULE_SELECTOR(DigitalBeatText::onTimeHandler), m_scheduleInterval);
}

void DigitalBeatText::stopRoll()
{
    unschedule(CC_SCHEDULE_SELECTOR(DigitalBeatText::onTimeHandler));
}

void DigitalBeatText::onTimeHandler(float dt)
{
    m_lastValue += m_valueGap;
    bool stop = false;
    if (!m_isReverse)
    {
        if (m_lastValue >= m_newValue){
            m_lastValue = m_newValue;
            stop = true;
        }
    }
    else{
        if (m_lastValue <= m_newValue){
            m_lastValue = m_newValue;
            stop = true;
        }
    }
    m_txt->setString(cocos2d::StringUtils::toString(m_lastValue));
    if (stop){
        this->stopRoll();
    }
}

使用示例：

    m_index = 1;
    m_beatT = DigitalBeatText::create(m_index);
    m_beatT->setPosition(visibleSize*0.5);
    this->addChild(m_beatT);
    
    m_index += RandomHelper::random_int(0, 100) - 50;
    m_beatT->setValue(m_index);

效果如图：