C# 最齐全的上传图片方法

public ActionResult Upload()    {      string imgurl = "";      foreach (string key in Request.Files)      {        //这里只测试上传第一张图片file[0]        HttpPostedFileBase file0 = Request.Files[key];        //转换成byte,读取图片MIME类型        Stream stream;        int size = file0.ContentLength / 1024; //文件大小KB        if (size > 1024)        {          return Content(ReturnMsg(Enum_Return.失败, "图片不能超过1M：", null));        }        byte[] fileByte = new byte[2];//contentLength，这里我们只读取文件长度的前两位用于判断就好了，这样速度比较快，剩下的也用不到。        stream = file0.InputStream;       stream.Read(fileByte, 0, 2);//contentLength，还是取前两位        //获取图片宽和高        //System.Drawing.Image image = System.Drawing.Image.FromStream(stream);        //int width = image.Width;        //int height = image.Height;        string fileFlag = "";        if (fileByte != null && fileByte.Length > 0)//图片数据是否为空        {          fileFlag = fileByte[0].ToString()  fileByte[1].ToString();        }        string[] fileTypeStr = { "255216", "7173", "6677", "13780" };//对应的图片格式jpg,gif,bmp,png        if (fileTypeStr.Contains(fileFlag))        {          string action = Request["action"];          string path = "/uploads/";          switch (action)          {            case "headimage":              path  = "headimage/";              break;            case "blogtype":              path  = "blogtype/";              break;          }          string fullpath = path  UserInfo.userID  "/";          if (!Directory.Exists(Server.MapPath(fullpath)))          {            Directory.CreateDirectory(Server.MapPath(fullpath));          }          Request.Files[key].SaveAs(Server.MapPath(fullpath  Request.Files[key].FileName));          imgurl = fullpath  Request.Files[key].FileName;        }        else        {          return Content(ReturnMsg(Enum_Return.失败, "图片格式不正确：" fileFlag, null));        }        stream.Close();      }      return Content(ReturnMsg(Enum_Return.成功, "上传成功", imgurl));    }

public void ProcessRequest(HttpContext context)  {    context.Response.ContentType = "application/json";    HttpPostedFile _upfile = context.Request.Files["File"];    if (_upfile.ContentLength < 500000)    {      if (string.IsNullOrEmpty(_upfile.FileName))      {         context.Response.Write("请上传图片");      }      string fileFullname = _upfile.FileName;      string dataName = DateTime.Now.ToString("yyyyMMddhhmmss");      string fileName = fileFullname.Substring(fileFullname.LastIndexOf("//")  1);      string type = fileFullname.Substring(fileFullname.LastIndexOf(".")  1);      if (type == "bmp" || type == "jpg" || type == "gif" || type == "JPG" || type == "BMP" || type == "GIF")      {        _upfile.SaveAs(HttpContext.Current.Server.MapPath("photo")  "//"  dataName  "."  type);        HttpCookie cookie = new HttpCookie("photo");        context.Response.Write("上传成功");      }      else      {        context.Response.Write("支持格式：|jpg|gif|bmp|");      }    }    else    {      context.Response.Write("你的图片已经超过500K的大小！");    }  }