技能冷却UGUI5.1

using UnityEngine;
using System.Collections;
using UnityEngine.UI;


public class SkillItem : MonoBehaviour
{
    public float coldTime = 2;
    public KeyCode keycode;
    private float timer = 0;
    private Image filledImage;
    private bool isStartTimer = false;
// Use this for initialization
void Start ()
{
   filledImage = transform.Find("FilledImage").GetComponent<Image>();
   Toggle toggle;
   ToggleGroup group;
}

// Update is called once per frame
void Update () {
   if (Input.GetKeyDown(keycode))
   {
       isStartTimer = true;
   }
   if (isStartTimer)
   {
       timer += Time.deltaTime;
       filledImage.fillAmount = (coldTime - timer)/coldTime;
       if (timer >= coldTime)
       {
           filledImage.fillAmount = 0;
           timer = 0;
           isStartTimer = false;
       }
   }
}


    public void OnClick()
    {
        isStartTimer = true;
    }
}