/// <summary>
/// 添加一个倒计时任务
/// </summary>
/// <param name="callback">回调</param>
/// <param name="totalTime">倒计时总时间(单位:秒)</param>
/// <returns>任务ID</returns>
public int AddCountdownTask(Action <int> callback, int totalTime)
{
return(timer.AddCountdownTask(callback, totalTime));
}