画像のアップロード（ファイルストリーム）

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using System.Drawing;
using System.Drawing.Imaging;
using System.Web.Hosting;

namespace TF.Common
{
    public  class UploadImage
    {
        
        /// <summary>
        /// 将Base64位码保存成图片
        /// </summary>
        /// <param name="UserPhoto">Base64位码</param>
        /// <returns></returns>
        public static string UploadImageByBase64String(string UserPhoto)
        {
            //if (!ModelState.IsValid)
            //{
            //    LogHelper.WriteLog(ErrorPrompt.ValidationFailure);
            //    return BadRequest(ModelState);
            //}
            
            string result;
            //图片路径
            string filePath = HttpContext.Current.Server.MapPath("~/" + @System.Configuration.ConfigurationManager.AppSettings["ImagePath"]);
            try
            {
                byte[] bt = Convert.FromBase64String(UserPhoto);//获取图片base64
                string fileName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString();//年月
                string ImageFilePath = "/Image" + "/" + fileName;
                if (System.IO.Directory.Exists(HttpContext.Current.Server.MapPath(ImageFilePath)) == false)//如果不存在就创建文件夹
                {
                    System.IO.Directory.CreateDirectory(HttpContext.Current.Server.MapPath(ImageFilePath));
                }
                string ImagePath = HttpContext.Current.Server.MapPath(ImageFilePath) + "/" + System.DateTime.Now.ToString("yyyyHHddHHmmss");//定义图片名称
                File.WriteAllBytes(ImagePath + ".jpg", bt); //保存图片到服务器，然后获取路径  
                result = ImagePath + ".jpg";//获取保存后的路径
            }
            catch (Exception e)
            {
                throw e;
            }
            //LogHelper.WriteLog(ErrorPrompt.Success);
            return result;
        }
        //用这个
        //用List集合保存传递过来的Base654格式的图片，前端是用数组存图片进行发送后端的
        //传递的是一个Data对象，我的控制器也用对象类型接受
        public static string UpLoadImg(string file)
        {
            //前端传递的data里的key必须和后台类里的字段保持一致，否则接受不到前端传递的数据
            //List<string> imgInfoList = funnyInfo.image;
            //string guids = funnyInfo.guid;
            if (file != null)
            {
                //图片保存的路径
                string imgPath = HostingEnvironment.MapPath("~/img/");
                string path="";
                string pathTwo = "";
                if (!Directory.Exists(imgPath))
                {
                    Directory.CreateDirectory(imgPath);
                }
                else
                {
                    Guid guid = Guid.NewGuid();
                    //将图片保存为jpg格式，图片名为guid.jpg
                     path =  guid + ".jpg";
                    //调用方法解析Base64编码的图片，并保存图片
                    Base64ToImg(file.Split(',')[1]).Save(imgPath + path);
                    pathTwo = "/img/"+ path;
                }
                return pathTwo;
            }
            else
            {
                return "-1";
            }
           
        }
        //解析base64编码获取图片
        private static Bitmap Base64ToImg(string base64Code)
        {
            MemoryStream stream = new MemoryStream(Convert.FromBase64String(base64Code));
            return new Bitmap(stream);
        }

      


    }
}