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;//10秒换一次
    public float ShowTimeTrigger = 0;//计时
    public float fadeTime = 3;
    public float fadeTimeTrigger = 0;
    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 >= 0 && fadeTimeTrigger <fadeTime)
            {
                fadeTimeTrigger += Time.deltaTime;
                if (show)
                {
                    image.color = new Color(1, 1, 1, 1 - (fadeTimeTrigger / fadeTime));

                }
                else
                {
                    image.color = new Color(1, 1, 1, (fadeTimeTrigger / fadeTime));

                }
            }
            else
            {
                fadeTimeTrigger = 0;
                ShowTimeTrigger = 0;
                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;//3秒换一次
    public float starttime = 0;//计时
    public float time = 0;
    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 >= 0 && time < 1)
            {
                time += Time.deltaTime;
                if (b)
                {
                image.color = new Color(1, 1, 1, 1 - time);
                }
                else
                {
                    image.color = new Color(1, 1, 1, time);
                }
            }
            else
            {
                time = 0;
                starttime = 0;
                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(1, 1, 1, 0), 5, true, true);