解决了困扰一周的问题2

  /// <summary>
        /// 根据对应的imgid 把base=>二进制=>存入数据库
        /// </summary>
        /// <param name="imgID"></param>
        /// <param name="imgbase"></param>
        /// <returns></returns>
        public ActionResult getbase(string imgID,string imgbase)
        {
            cb.imageID = Convert.ToInt32(imgID);
            Encoding.Default.GetBytes(imgbase);
            byte[] imgbyte = System.Convert.FromBase64String(imgbase);
            //第一种可以这样
            //System.IO.File.WriteAllBytes(@"E:	est1.jpg", imgbyte);
            cb.base64 = imgbyte;
            //第二种
            //MemoryStream ms = new MemoryStream(imgbyte);
            //FileStream fs = new FileStream(@"E:	est1.jpg", FileMode.Create);
            //ms.WriteTo(fs);
            //ms.Close();
            //fs.Close();
            
            int result = cm.clipImg(cb);
            if (result > 0)
            {
                ViewData["msg"] = "成功";
            }
            else
            {
                ViewData["msg"] = "失败";
            }
            return View();
        }
        /// <summary>
        /// 根据id 得到图片
        /// </summary>
        /// <param name="imgID"></param>
        /// <returns></returns>
        public FileResult getimg(string imgID)
        {
            int imageID = 8;
            
            ClipBase64 cate = cm.getimg(imageID);
            if (cate != null)
            {
                return File(cate.base64, "image/jpg", "Imag1");
            }
            else { return null; }
        }

DAL层：

/// <summary>
        /// 裁剪图片插入数据库
        /// </summary>
        /// <param name="cb"></param>
        /// <returns></returns>
        public int clipImg(ClipBase64 cb)
        {
            string sql = "INSERT INTO ClipBase64(ImageId,base64)values(@imageID,@base64)";
            SqlParameter[] pars = new SqlParameter[2];
            pars[0] = new SqlParameter("@imageID", cb.imageID);
            pars[1] = new SqlParameter("@base64", cb.base64);
            int result = SqlHelper.ExecuteNoQuery(sql, CommandType.Text, pars);
            return result;
        } 
        /// <summary>
          /// 得到图片
          /// </summary>
          /// <returns></returns>
        public ClipBase64 getimg(int id)
        {
            string sql = "select base64 from ClipBase64 where ImageId=@id" ;
            SqlParameter[] par = new SqlParameter[1];
            par[0] = new SqlParameter("@Id", id);
            DataTable dt = SqlHelper.ExecuteDataTable(sql, CommandType.Text, par);
            DataRow dr = dt.Rows[0];
            ClipBase64 c = new ClipBase64();
            //c.imageID = Convert.ToInt32(dr["AdminId"]);
            c.base64 = (byte[])(dr["base64"]);
            return c;
        }