Unity中播放gif

unity自身是不支持gif图片的播放，首先复制"System.Drawing.dll"文件在 "C:\Program Files (x86)\Unity\Editor\Data\Mono\lib\mono\2.0"文件到"Assets" 文件夹下面，播放的原理其实就是把GIF图片，转换为一张一张的图片，在播放出来。

代码：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System;

/// <summary>
/// Unity播放GIf动画
/// </summary>
public class GifPlayer : MonoBehaviour {

    public System.Drawing.Image gifImage;       //gif图片
    public UnityEngine.UI.Image image;          //显示gif的UI
    public string windowPath = "game_start.gif";                  //windons的gif的路径
    public string EditorPath = "game_start.gif";                   //Editor的路径

    private float fps = 15;
    private List<Texture2D> text2DList;         //gif拆成的图片
    private float time;

	void Start () {
        //打包时路径     需要将gif图片放在StreamingAssets里
        gifImage = System.Drawing.Image.FromFile(Application.streamingAssetsPath + "/" + windowPath);

        ////编译器下或者Iphone平台
        //gifImage = System.Drawing.Image.FromFile(Application.dataPath + "/" + EditorPath);
        text2DList = GifToTexture2D(gifImage);
	}

    List<Texture2D> GifToTexture2D(System.Drawing.Image gifImage)
    {
        List<Texture2D> target = null;
        if (gifImage != null)
        {
            target = new List<Texture2D>();
            //Debug.Log("dimenson:" + gifImage.FrameDimensionsList.Length);

            FrameDimension frameDimension = new FrameDimension(gifImage.FrameDimensionsList[0]);

            int frameCount = gifImage.GetFrameCount(frameDimension);
            for (int i = 0; i < frameCount; i++)
            {
                gifImage.SelectActiveFrame(frameDimension,i);
                //创建Bitmap的实例
                Bitmap frameBitmap = new Bitmap(gifImage.Width, gifImage.Height);
                //Save
                //frameBitmap.Save(Application.dataPath + "/" + i + ".png", ImageFormat.Png);
                //将GifImage通过Graphics画到Bitmap上
                using (System.Drawing.Graphics graphics = System.Drawing.Graphics.FromImage(frameBitmap))
                {
                    graphics.DrawImage(gifImage, Point.Empty);
                }
                //创建Texture2D的实例
                Texture2D frameTexture2D = new Texture2D(frameBitmap.Width, frameBitmap.Height, TextureFormat.ARGB32, true);
                frameTexture2D.LoadImage(Bitmap2Byte(frameBitmap));
                target.Add(frameTexture2D);
            }
        }
        return target;
    }

    private byte[] Bitmap2Byte(Bitmap bitmap)
    {
        using (MemoryStream stream = new MemoryStream())
        {
            //将bitmap可以以png格式保存到流中
            bitmap.Save(stream, ImageFormat.Png);
            //创建一个字节数组，长度为流的长度
            byte[] data = new byte[stream.Length];
            //重置指针
            stream.Seek(0, SeekOrigin.Begin);
            //从流读取字节数组块存入data中
            stream.Read(data, 0, Convert.ToInt32(stream.Length));
            return data;

        }
    }

	void Update () {
        if (text2DList.Count > 0)
        {
            time += Time.deltaTime;
            int index = (int)(time * fps) % text2DList.Count;
            if (image != null)
            {
                Sprite sprite = Sprite.Create(text2DList[index],
                    new Rect(0, 0, text2DList[index].width, text2DList[index].height),
                    new Vector2(0.5f, 0.5f));
                image.overrideSprite = sprite;
            }
        }
	}
}