Question

我是ASP MVC的新手，我一直在尝试将位图文件从硬盘上传到C＃Bitmap对象，我稍后将其分配给我的模型。

视图（cshtml文件）如下所示：

    <form action = "DisplayAddedPicture" method=post>
    <input type=file name="Picture" id = "Picture"/>
    <input type=submit value="Send!" />
    </form>

来自控制器的DisplayAddedPicture方法：

        [HttpPost]
        public ActionResult DisplayAddedPicture()
        {
          HttpPostedFileBase File = Request.Files["Picture"];

          if (File == null) throw new Exception("NullArgument :( ");

          // file stream to byte[]
          MemoryStream target = new MemoryStream();
          File.InputStream.CopyTo(target);
          byte[] TempByteArray = target.ToArray();

          // byte[] to Bitmap
          ImageConverter imageConverter = new ImageConverter();
          Image TempImage = (Image)imageConverter.ConvertFrom(TempByteArray);
          Bitmap FinalBitmap = new Bitmap(TempImage);

          // (...)
        }

事实证明，每次我得到的都是异常，因为HttpPostedFileBase对象始终为null。在我的逻辑中是否存在任何流动（除了之后发生的所有转换，我知道它们是混乱的）或者还有其他方法可以解决这个问题吗？

Answer 1

试试这个

在您的视图中，

@using (Html.BeginForm("DisplayAddedPicture", "YourControllerName", 
                      FormMethod.Post, new { enctype = "multipart/form-data" }))
{
     <input type=file name="Picture" id = "Picture"/>
     <input type=submit value="Send!" />
}

动作方法

[HttpPost] 
public ActionResult DisplayAddedPicture(HttpPostedFileBase Picture)
{
  if (Picture!= null && Picture.ContentLength > 0) 
  {
      //Do some thing with the Picture object
      //try to save the file here now.
      //After saving follow the PRG pattter (do a redirect)

      //return RedirectToAction("Uploaded");
  }  
  return View();
}

Answer 2

尝试将以下内容添加到表单标记中：enctype="multipart/form-data"

<form method="post" action="DisplayAddedPicture" enctype="multipart/form-data">

    <input type=file name="Picture" id = "Picture"/>
    <input type=submit value="Send!" />

</form>

如何从HDD获取文件到Bitmap对象[ASP MVC 3]？

2 个答案: