cc.progressFromTo cc.progressTo（action 在duration中ProgressTimer的Percentage变化)

let progressTimer= new cc.ProgressTimer(new cc.Sprite(fileName));
this.addChild(progressTimer);
progressTimer.setType(cc.ProgressTimer.TYPE_RADIAL);//圆形进度条
//progressTimer.setReverseDirection(true);是顺时针方向还是逆时针方向(对于圆形进度条来说)

progressTimer.runAction(cc.progressFromTo(duration, fromPercentage, toPercentage));//在duration中，progressTimer显示的percentage从fromPercentage变为toPercentage
progressTimer.runAction(cc.progressFromTo(5, 0, 100));
progressTimer.runAction(cc.progressTo(2, 80));