C# 图片上传，下载，显示汇总

1.图片上传和显示 c# ASP.NET MVC easyui-filebox 图片上传和显示 - Tozhang - 博客园 (cnblogs.com)

2.下载http或fpt图片、文件  C# 下载PDF文件（http与ftp） - Tozhang - 博客园 (cnblogs.com)

3.图片数据流 下载

var qrCode = QRCodeHelper.CreateQRCode(d);//二维码数据流byte
                var savePath = Guid.NewGuid().ToString("D") + ".png";
                string filePath = System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Image\\" + savePath);
                //创建文件夹
                var folderPath = filePath.Substring(0, filePath.LastIndexOf('\\'));
                ////FileHelper.CreateDir(folderPath);
                if (!Directory.Exists(folderPath))
                {
                    Directory.CreateDirectory(folderPath);
                }
                var suffixName = ImageFormat.Png;
                byte[] bytes = qrCode;
                using (MemoryStream mem = new MemoryStream(bytes))
                {
                    Bitmap bmp = new Bitmap(mem);
                    //保存到磁盘文件
                    bmp.Save(filePath, suffixName);
                    bmp.Dispose();
                }

4.http下载图片直接保存

private void btnPost_Click(object sender, EventArgs e)
       {
            string filePath = AppDomain.CurrentDomain.BaseDirectory + "Picture\\" + title + "\\";

            string dir = Path.GetDirectoryName(filePath);
            if (!Directory.Exists(dir))
            {
                Directory.CreateDirectory(dir);
            }

            if (Path.GetExtension(url) == ".jpg")
                return;
            var img = UrlToImage(url);
            img.Save(filePath + "//" + index + Path.GetExtension(url));
            UpdateLB("Success:" + title + "：" + url);
            //Trace.WriteLine("Success:" + models.Title + "：" + item);
            
       }

public static Image UrlToImage(string url)
    {
        WebClient mywebclient = new WebClient();
        byte[] Bytes = mywebclient.DownloadData(url);
        using (MemoryStream ms = new MemoryStream(Bytes))
        {
            Image outputImg = Image.FromStream(ms);
            return outputImg;
        }
    }