UGUI DOTween渐隐渐现

Tween tweenAlpha;

tweenAlpha = DOTween.To(() => MaskSpr.fillAmount, x => MaskSpr.fillAmount = x, 1f, RISE_TIME).OnComplete(() =>                                                                                                           {       tweenAlpha = DOTween.ToAlpha(() => MaskSpr.color, x => MaskSpr.color = x, 0f, DISAPPEAR_TIME).OnComplete(() =>                                                                                                  {        tweenAlpha = DOTween.ToAlpha(() => MaskSpr.color, x => MaskSpr.color = x, 1f, APPEAR_TIME).OnComplete(() =>{         State = SelState.done;        });       });      });