/// <summary>
/// 淡出所有图片【需要与RemoveAllPic连用】
/// </summary>
/// <param name="fadeout">淡出时间s（默认0.3s）</param>
public EffectPiece FadeoutAllPic(float fadeout = 0.5f)
{
Queue <NewImageEffect> effects = new Queue <NewImageEffect>();
effects.Enqueue(NewEffectBuilder.FadeOutAllPic(fadeout));
return(new EffectPiece(id++, effects));
}