本示例使用BestHTTP插件请求url地址下载至本地，并做缓存管理，易于扩展
using System; using UnityEngine; using BestHTTP; using System.IO; using System.Security.Cryptography; public class DownloadCachesMgr : Singleton<DownloadCachesMgr> { public string AssetCachesDir { get { string dir = ""; #if UNITY_EDITOR dir = Application.dataPath + "Caches/";//路径：/AssetsCaches/ #elif UNITY_IOS dir = Application.temporaryCachePath + "/Download/";//路径：Application/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/Library/Caches/ #elif UNITY_ANDROID dir = Application.persistentDataPath + "/Download/";//路径：/data/data/xxx.xxx.xxx/files/ #else dir = Application.streamingAssetsPath + "/Download/";//路径：/xxx_Data/StreamingAssets/ #endif return dir; } } public string ImagePathName { get { return AssetCachesDir + "Image/"; } } public string TextPathName { get { return AssetCachesDir + "Config/"; } } private string GetFileName(string url) { string name = StrToMD5(url); return name; } public static string StrToMD5(string str) { byte[] data = System.Text.Encoding.GetEncoding("GB2312").GetBytes(str); MD5 md5 = new MD5CryptoServiceProvider(); byte[] OutBytes = md5.ComputeHash(data); string OutString = ""; for (int i = 0; i < OutBytes.Length; i++) { OutString += OutBytes[i].ToString("x2"); } // return OutString.ToUpper(); return OutString.ToLower(); } private bool CheckFileExists(string path , string name) { if (!Directory.Exists(path)) { Directory.CreateDirectory(path); } FileInfo t = new FileInfo(path + "//" + name); if (!t.Exists) { return false; } else { return true; } } private void CreateFile(string path, string name,byte[] bytes) { if (!Directory.Exists(path)) { Directory.CreateDirectory(path); } FileStream fs; FileInfo t = new FileInfo(path + "//" + name); if (!t.Exists) { fs = t.Create(); } else { t.Delete(); fs = t.Create(); } fs.Write(bytes, 0, bytes.Length); fs.Close(); fs.Dispose(); } public void LoadImage(string url, Action<int, Texture2D> callBack) { string name = GetFileName(url); if (CheckFileExists(ImagePathName,name)) { var bytes = File.ReadAllBytes(ImagePathName + "//" + name); Texture2D tex = new Texture2D(0,0); tex.LoadImage(bytes); callBack(0, tex); } else { new HTTPRequest(new Uri(url), (request, response) => { if (request.State == HTTPRequestStates.Finished) { int result = 0; Texture2D tex = null; if (response.IsSuccess) { byte[] bytes = response.Data; CreateFile(ImagePathName, name, bytes); tex = new Texture2D(0,0); tex.LoadImage(bytes); callBack(result, tex); } else { result = response.StatusCode; } if (callBack != null) { callBack(result, tex); } } }).Send(); } } }