在屏幕上绘制字符串

        CCLabelTTF* pLabel = CCLabelTTF::create("Game Begin", "Arial", 24);
        CC_BREAK_IF(! pLabel);

        // Get window size and place the label upper.
        CCSize size = CCDirector::sharedDirector()->getWinSize();
        pLabel->setPosition(ccp(size.width / 2, size.height - 50));

        // Add the label to HelloWorld layer as a child layer.
  this->addChild(pLabel, 1);