u3d c# 写一个通用倒计时器

using UnityEngine;
using System.Collections;
using System;

public class TimerManager : MonoBehaviour 
{

    private static TimerManager m_instance = null;
    public static TimerManager Instance { get { return m_instance; } }

    void Awake()
    {
        m_instance = this;
    }
	// Use this for initialization
	void Start () {
	    
	}
	
	// Update is called once per frame
	void Update () {
	
	}

    public void GetTimer(int second,MyTimer.Mode mode,MyTimer.TimesUp TimesUpDelegate,MyTimer.PerSecond PerSecondDelegate=null)
    {
  GameObject Timer = Instantiate(Resources.Load("Prefabs/Time/MyTimer")) as GameObject;
        Timer.transform.parent = transform;

        Timer.GetComponent<MyTimer>().SetTimer(second);
        Timer.GetComponent<MyTimer>().SetMode(mode);
        Timer.GetComponent<MyTimer>().SetTimesUpDelegate(TimesUpDelegate);
        Timer.GetComponent<MyTimer>().SetPerSecondDelegate(PerSecondDelegate);
        Timer.GetComponent<MyTimer>().StartTimer();
    }
   public String GetTimeBySecond(float seconds)
    {
        return DateTime.Parse(DateTime.Now.ToString("00:00:00")).AddSeconds(seconds).ToString("HH:mm:ss");
    }
}

using UnityEngine;using System.Collections;public class MyTimer : MonoBehaviour {    public enum Mode    {        PerSecond,        Once,        Loop    }    public float TotalSeconds;    public Mode m_mode;    public delegate void TimesUp();    public TimesUp timesUp = null;    public delegate void PerSecond(float timesLeft);    public PerSecond perSecond = null;    int m_leaveSeconds;  void Awake()    {    }	// Use this for initialization	void Start () {		}		// Update is called once per frame	void Update () {		}  public void StartTimer()    {        switch (m_mode)        {            case Mode.PerSecond:                StartCoroutine(TimerBeginPerSocond());                break;            case Mode.Once:                StartCoroutine(TimerBegin());                break;            case Mode.Loop:                break;        }                    }  public void SetTimer(int seconds)    {        TotalSeconds = seconds;    }    public void SetMode(Mode mode)    {        m_mode = mode;    }    public void SetTimesUpDelegate(TimesUp del)    {        timesUp = del;    } public void SetPerSecondDelegate(PerSecond del)    {        perSecond = del;    }    IEnumerator TimerBegin()    {        yield return new WaitForSeconds(TotalSeconds);        timesUp();        Destroy(gameObject);    }  IEnumerator TimerBeginPerSocond()    {        yield return new WaitForSeconds(1f);        if ((TotalSeconds--) > 0)        {            perSecond(TotalSeconds);            StartCoroutine(TimerBeginPerSocond());        }        else        {            timesUp();            Destroy(gameObject);        }    }    }

    public void CreateTimerManager()    {        GameObject TimerManager = GameObject.Instantiate(Resources.Load("Prefabs/Manager/TimerManager")) as GameObject;        TimerManager.name = "TimerManager";    }