CD冷却效果实现

using UnityEngine;
using System.Collections;

public class CDCold : MonoBehaviour {

    private float coldTime=2;
    private bool isColding=false;
    private UISprite sprite;

    // Use this for initialization
    void Awake () {
        sprite = transform.Find ("Sprite").GetComponent<UISprite> ();
    }
    
    // Update is called once per frame
    void Update () {
    if (Input.GetKey (KeyCode.Y) && isColding == false) 
        {
            isColding=true;
            sprite.fillAmount=1;
        }
        if (isColding) 
        {
            sprite.fillAmount-=(1.0f/coldTime)*Time.deltaTime;
            if(sprite.fillAmount<=0.0f)
            {
                sprite.fillAmount=0;
                isColding=false;
            }
        }
    }
}