93 lines
2.7 KiB
C#
93 lines
2.7 KiB
C#
|
using UnityEngine;
|
|||
|
using UnityEngine.UI;
|
|||
|
using System.Collections;
|
|||
|
using System.IO;
|
|||
|
|
|||
|
public class AsyncImageDownload : MonoBehaviour
|
|||
|
{
|
|||
|
public Sprite myWXPic;
|
|||
|
|
|||
|
private static AsyncImageDownload _instance = null;
|
|||
|
public static AsyncImageDownload GetInstance()
|
|||
|
{ return Instance; }
|
|||
|
public static AsyncImageDownload Instance
|
|||
|
{
|
|||
|
get
|
|||
|
{
|
|||
|
if (_instance == null)
|
|||
|
{
|
|||
|
GameObject obj = new GameObject("AsyncImageDownload");
|
|||
|
_instance = obj.AddComponent<AsyncImageDownload>();
|
|||
|
DontDestroyOnLoad(obj);
|
|||
|
_instance.Init();
|
|||
|
}
|
|||
|
return _instance;
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
public bool Init()
|
|||
|
{
|
|||
|
if (!Directory.Exists(Application.persistentDataPath + "/ImageCache/"))
|
|||
|
{
|
|||
|
Directory.CreateDirectory(Application.persistentDataPath + "/ImageCache/");
|
|||
|
}
|
|||
|
myWXPic = null;
|
|||
|
return true;
|
|||
|
|
|||
|
}
|
|||
|
|
|||
|
public void SetAsyncImage(string url, Image image)
|
|||
|
{
|
|||
|
//开始下载图片前,将UITexture的主图片设置为占位图
|
|||
|
if (myWXPic != null)
|
|||
|
{
|
|||
|
image.sprite = myWXPic;
|
|||
|
return;
|
|||
|
}
|
|||
|
|
|||
|
//判断是否是第一次加载这张图片
|
|||
|
if (!File.Exists(path + url.GetHashCode()))
|
|||
|
{
|
|||
|
//如果之前不存在缓存文件
|
|||
|
StartCoroutine(DownloadImage(url, image));
|
|||
|
}
|
|||
|
else
|
|||
|
{
|
|||
|
StartCoroutine(LoadLocalImage(url, image));
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
IEnumerator DownloadImage(string url, Image image)
|
|||
|
{
|
|||
|
Debug.Log("downloading new image:" + path + url.GetHashCode());//url转换HD5作为名字
|
|||
|
WWW www = new WWW(url);
|
|||
|
yield return www;
|
|||
|
Texture2D tex2d = www.texture;
|
|||
|
//将图片保存至缓存路径
|
|||
|
byte[] pngData = tex2d.EncodeToPNG(); //将材质压缩成byte流
|
|||
|
File.WriteAllBytes(path + url.GetHashCode(), pngData); //然后保存到本地
|
|||
|
Sprite m_sprite = Sprite.Create(tex2d, new Rect(0, 0, tex2d.width, tex2d.height), new Vector2(0, 0));
|
|||
|
image.sprite = m_sprite;
|
|||
|
myWXPic = m_sprite;
|
|||
|
}
|
|||
|
|
|||
|
IEnumerator LoadLocalImage(string url, Image image)
|
|||
|
{
|
|||
|
string filePath = "file:///" + path + url.GetHashCode();
|
|||
|
WWW www = new WWW(filePath);
|
|||
|
yield return www;
|
|||
|
Texture2D texture = www.texture;
|
|||
|
Sprite m_sprite = Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height), new Vector2(0, 0));
|
|||
|
image.sprite = m_sprite;
|
|||
|
myWXPic = m_sprite;
|
|||
|
}
|
|||
|
|
|||
|
public string path
|
|||
|
{
|
|||
|
get
|
|||
|
{
|
|||
|
//pc,ios //android :jar:file//
|
|||
|
return Application.persistentDataPath + "/ImageCache/";
|
|||
|
}
|
|||
|
}
|
|||
|
}
|