Question

我正在尝试调试一段时间前我已经建立的异步文件上传器，它不再有效，我花了很多时间没有成功。

服务器正在接收的流总是被破坏，实际上我保存的文件（图像）无法打开。

为简化调试，我设置了一个全新的ASP.NET项目，包含两个主要文件，带有表单字段的HTML文件和ASP.NET处理程序。

尽管这里的代码非常简单，但我还是运气不好！：（

非常感谢任何帮助，非常感谢！

<!DOCTYPE html>
<html>
<head>
    <title>Upload Files using XMLHttpRequest - Minimal</title>

    <script type="text/javascript">

      function uploadFile() {
        var fd = new FormData();
        fd.append("fileToUpload", document.getElementById('fileToUpload').files[0]);
        var xhr = new XMLHttpRequest();

        xhr.addEventListener("load", uploadComplete, false);
        xhr.addEventListener("error", uploadFailed, false);
        xhr.addEventListener("abort", uploadCanceled, false);
        xhr.open("POST", "Handler1.ashx");
        xhr.send(fd);
      }

      function uploadComplete(evt) {
        /* This event is raised when the server send back a response */
        alert(evt.target.responseText);
      }

      function uploadFailed(evt) {
        alert("There was an error attempting to upload the file.");
      }

      function uploadCanceled(evt) {
        alert("The upload has been canceled by the user or the browser dropped the connection.");
      }
    </script>
</head>
<body>
  <form id="form1" enctype="multipart/form-data" method="post" action="Handler1.ashx">

      <input type="file" name="fileToUpload" id="fileToUpload"/>
      <input type="button" onclick="uploadFile()" value="Upload" />

  </form>
</body>
</html>

这是ashx处理程序：

using System;
using System.Collections.Generic;
using System.Web.Extensions;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.IO;
namespace MultipleFileUploadTest
{
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class Handler1 : IHttpHandler
    {
        public void ProcessRequest(HttpContext context)
        {
            var stream = context.Request.InputStream;

            MemoryStream memoryStream;

            ReadFully(stream, out memoryStream);

            Byte[] ba = memoryStream.ToArray();


            var path = @"C:\Users\giuseppe.JHP\Desktop\Image upload test\uploaded.gif";


            using (FileStream fs = new FileStream(path, FileMode.OpenOrCreate))
            {
                fs.Write(ba, 0, ba.Length);
            }

            //DEBUGGING CODE
            //I'm opening the same file that was originally picked by the input form field and I'm now comparing the original file with the one received within the context stream. They always differ!
            Byte[] ba2 = File.ReadAllBytes(@"C:\Users\giuseppe.JHP\Desktop\Image upload test\a.gif");

            //equal evaluates always to false
            bool equal = ba.Length == ba2.Length;

            if (equal)
            {
                for (var i = 0; i < ba2.Length; i++)
                {
                    if (ba[i] != ba2[i])
                    {
                        equal = false;
                        i = ba2.Length;
                    }
                }

            }

            //equal is always false
            //if (!equal)
            //{
            //   throw Exception("Stream is not valid");
            //}
            //The code below will throw a Parameter is invalid exception
            //System.Drawing.Image mediaObject = System.Drawing.Image.FromStream(memoryStream);


            memoryStream.Close();
        }

        public static void ReadFully(Stream input, out MemoryStream ms)
        {
            ms = new MemoryStream();
            byte[] buffer = new byte[16 * 1024];

            int read;
            while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
            {
                ms.Write(buffer, 0, read);
            }
        }
        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}

Answer 1

如果它帮助了其他人，我已经让代码工作了，这就是它的变化：

    public void ProcessRequest(HttpContext context)
    {
        if (context.Request.Files != null && context.Request.Files.Count > 0)
        {
            var file = context.Request.Files[0];

            file.SaveAs(@"C:\Users\giuseppe.JHP\Desktop\Image upload test\uploaded.gif");
        }
    }

HTML5异步文件上传，上传的流始终无效

1 个答案: