ET/Unity/Assets/Scripts/Codes/Model/Client/Helper/UrlImageLoader.cs

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Net;
using System.Threading.Tasks;
using UnityEngine;

namespace ET
{
    public class UrlImageLoader: Singleton<UrlImageLoader>//, ISingletonAwake
    {
        const string ImgPrefix = "omm_di_";

        private int FileIndex = 0;
        private string TmpImgFile(String url)
        {
            string ext = ".png";
            if (url.EndsWith(".jpg") || url.EndsWith(".png") || url.EndsWith(".gif"))
            {
                ext = url.Substring(url.Length - 4);
            }
            var file = ImgPrefix + (++FileIndex) + ext;
            return Path.Combine(Application.persistentDataPath, file);
        }


        public async Task<Texture2D> LoadImage(string url)
        {
            try
            {
                var imgFile = TmpImgFile(url);
                await new WebClient().DownloadFileTaskAsync(url, imgFile);

                var stream = new FileStream(imgFile, FileMode.Open, FileAccess.Read);
                Image img = Image.FromStream(stream);
                Texture2D tex = new Texture2D(img.Width, img.Height);
                img.Dispose();

                stream.Seek(0, SeekOrigin.Begin);
                var bytes = new Byte[stream.Length];
                stream.Read(bytes, 0, bytes.Length);
                ImageConversion.LoadImage(tex, bytes, false);

                stream.Close();
                return tex;
            }
            catch(Exception e) 
            {
                Log.Error($"Load error: url\n" + e);
            }

            return null;  
        }
    }
}