UI界面之淡入淡出

1.
using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class danrudanchu : MonoBehaviour
{
    public Image image;
    public float showTime = ;//10秒换一次
    public float ShowTimeTrigger = ;//计时
    public float fadeTime = ;
    public float fadeTimeTrigger = ;
    private bool show = true;
    // Use this for initialization
    void Start()
    {

    }
    // Update is called once per frame
    void Update()
    {
        ShowTimeTrigger += Time.deltaTime;//计时
        if (ShowTimeTrigger > showTime)
        {
            if (fadeTimeTrigger >=  && fadeTimeTrigger <fadeTime)
            {
                fadeTimeTrigger += Time.deltaTime;
                if (show)
                {
                    image.color = new Color(, , ,  - (fadeTimeTrigger / fadeTime));

                }
                else
                {
                    image.color = new Color(, , , (fadeTimeTrigger / fadeTime));

                }
            }
            else
            {
                fadeTimeTrigger = ;
                ShowTimeTrigger = ;
                if (show)
                {
                    show = false;
                }
                else
                {
                    show = true;
                }
            }
        }

    }
}

2.

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

public class danruchu : MonoBehaviour {
    public Image image;
    public float showTime = ;//3秒换一次
    public float starttime = ;//计时
    public float time = ;
    bool b = true;
    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {
        starttime+= Time.deltaTime;
        if (starttime > showTime)
        {
            if (time >=  && time < )
            {
                time += Time.deltaTime;
                if (b)
                {
                image.color = new Color(, , ,  - time);
                }
                else
                {
                    image.color = new Color(, , , time);
                }
            }
            else
            {
                time = ;
                starttime = ;
                if (b)
                {
                    b = false;

                }
                else
                {
                    b = true;
                }
            }
        }

    }
}

3.

这也可以淡入淡出：
//this.gameObject.GetComponent<Image>().CrossFadeAlpha(0, 5, false);
        GetComponent<Image>().CrossFadeColor(new Color(, , , ), , true, true);