asp.net MVC上传图片完整方法

图片上传 自动创建文件夹并重命名（带缩略图）

后台：

        [HttpPost]
        public ActionResult WanSell_UploadPicture(ProductGalleryModels picturegm)
        {

            var users = Session["onlineUsers"] as List<CurrentOnlineUsers>;
            string usename = users[].CUserName.ToString();              //获取用户名
            string randomName = DateTime.Now.ToFileTime().ToString();   //系统当前时间为图片名称
            HttpPostedFileBase file = Request.Files["fileToUpload"];//获取客户端上传的图片
            string pictureName = file.FileName;                          //上传图片的原名
            string extensionName = System.IO.Path.GetExtension(pictureName);//获取扩展名
            int randomcode = BaseRandom.GetRandom(, );                //产生随机数
            string newName = string.IsNullOrEmpty(pictureName.Trim()) ? "" : usename + randomcode + randomName + System.IO.Path.GetExtension(pictureName);                                                                //重命名图片
            if (picturegm.ImgDescription != null && picturegm.ImgDescription != "")     //附加判断图片描述是否为空
            {
                if (extensionName.ToLower() == "jpg" || extensionName.ToLower() == "bmp" || extensionName.ToLower() == "gif")   //判断图片格式
                {
                    string savePath = HttpContext.Server.MapPath("~/Content/Uploads/img/" + usename);     //原图图片保存位置
                    string smalfilepath = Server.MapPath("~/Content/Uploads/smallimg/" + usename);         //缩略图图片保存位置
                    if (!System.IO.Directory.Exists(savePath))
                    {
                        //如果路径不存在创建新文件夹
                        System.IO.Directory.CreateDirectory(savePath);
                    }
                    if (!System.IO.Directory.Exists(smalfilepath))
                    {
                        System.IO.Directory.CreateDirectory(smalfilepath);
                    }
                    file.SaveAs(savePath + '/' + newName);                                                                           //将上传的文件保存到指定的目录。
                    FileFolder.MakeThumbnail(savePath + '/' + newName, smalfilepath + '/' + newName, , , "Cut");
                    ViewData["messageBox"] = "上传成功";
                    return View("~/Views/RechargeMoney/RechargeSuccess.cshtml");
                }
                else
                {
                    ModelState.AddModelError("", "图片格式应为jpg/bmp/gif");
                }
            }
            else
            {
                ModelState.AddModelError("", "请填写图片描述");
            }
            return View("~/Views/IWantSell/WanSell_UploadPicture.cshtml");
        }
        #endregion

Controller Code

缩略图类：

 #region 生成缩略图

         /**/

         /// <summary>

         /// 生成缩略图

         /// </summary>

         /// <param name="originalImagePath">源图路径（物理路径）</param>

         /// <param name="thumbnailPath">缩略图路径（物理路径）</param>

         /// <param name="width">缩略图宽度</param>

         /// <param name="height">缩略图高度</param>

         /// <param name="mode">生成缩略图的方式</param>    

         public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)

         {

             System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);

             int towidth = width;

             int toheight = height;

             int x = ;

             int y = ;

             int ow = originalImage.Width;

             int oh = originalImage.Height;

             switch (mode)

             {

                 case "HW"://指定高宽缩放（可能变形）                

                     break;

                 case "W"://指定宽，高按比例                    

                     toheight = originalImage.Height * width / originalImage.Width;

                     break;

                 case "H"://指定高，宽按比例

                     towidth = originalImage.Width * height / originalImage.Height;

                     break;

                 case "Cut"://指定高宽裁减（不变形）                

                     if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)

                     {

                         oh = originalImage.Height;

                         ow = originalImage.Height * towidth / toheight;

                         y = ;

                         x = (originalImage.Width - ow) / ;

                     }

                     else

                     {

                         ow = originalImage.Width;

                         oh = originalImage.Width * height / towidth;

                         x = ;

                         y = (originalImage.Height - oh) / ;

                     }

                     break;

                 default:

                     break;

             }

             //新建一个bmp图片

             System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);

             //新建一个画板

             System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);

             //设置高质量插值法

             g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

             //设置高质量,低速度呈现平滑程度

             g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

             //清空画布并以透明背景色填充

             g.Clear(System.Drawing.Color.Transparent);

             //在指定位置并且按指定大小绘制原图片的指定部分

             g.DrawImage(originalImage, new System.Drawing.Rectangle(, , towidth, toheight),

                 new System.Drawing.Rectangle(x, y, ow, oh),

                 System.Drawing.GraphicsUnit.Pixel);

             try

             {

                 //以jpg格式保存缩略图

                 bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);

             }

             catch (System.Exception e)

             {

                 throw e;

             }

             finally

             {

                 originalImage.Dispose();

                 bitmap.Dispose();

                 g.Dispose();

             }

         }

         #endregion

缩略图 Code