asp.net-mvc - 需要帮助使用 ASP.NET MVC2 调试基于 XHR 的 Ajax 图像上传

Question

我正在尝试使用从 http://valums.com/ajax-upload/ 找到的脚本

我的 Controller 如下

using System;
using System.IO;
using System.Text.RegularExpressions;
using System.Web;
using System.Web.Hosting;
using System.Web.Mvc;
using MHNHub.Areas.ViewModels;
using MHNHub.Models;
using MHNHub.ViewModels;

namespace MHNHub.Areas.Admin.Controllers
{
    [Authorize(Roles = "Administrator")]
    public class ImageController : Controller
    {

        private MHNHubEntities _entities = new MHNHubEntities();

        //
        // GET: /Image/
        [AcceptVerbs(HttpVerbs.Get)]
        public ActionResult ImageUploader()
        {
            var viewModel = new ImageViewModel()
            {
                Image = new Image()
            };

            return PartialView(viewModel);
        }

        [AcceptVerbs(HttpVerbs.Post)]
        public ActionResult ImageUploader(Image image)
        {
            try
            {
                _entities.Images.AddObject(image);
                _entities.SaveChanges();

                return RedirectToAction("Index", "Product");
            }
            catch (Exception ex)
            {
                var viewModel = new ImageViewModel()
                                {
                                    Image = image,
                                    HasError = true,
                                    ErrorMessage = ex.Message
                                };
                return PartialView(viewModel);

            }
        }

        private string _uploadsFolder = HostingEnvironment.MapPath("~/App_Data/Files");

        public Guid Upload(HttpPostedFileBase fileBase)
        {
            var identifier = Guid.NewGuid();
            fileBase.SaveAs(GetDiskLocation(identifier));
            return identifier;
        }

        private string GetDiskLocation(Guid identifier)
        {
            return Path.Combine(_uploadsFolder, identifier.ToString());
        }

    }

}

我有这样的局部 View

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<MHNHub.ViewModels.ImageViewModel>" %>

<script type="text/javascript">
    $(function () {
        $("#imagedialog").dialog({
            bgiframe: true,
            height: 170,
            width: 430,
            modal: true,
            autoOpen: false,
            resizable: true
        })
    });

    $(document).ready(function createUploader() {
        var uploader = new qq.FileUploader({
            element: document.getElementById('fileuploader'),
            action: '/Image/Upload/',
            name: 'name'
        });

    });

</script>    

<div id="imagedialog" title="Upload Image">

                <div id="fileuploader">

                </div>
                <h6>Drag and drop files supported in Firefox and Google Chrome with javascript enabled.</h6> 
                    <noscript>
                         <form action="/image/upload" enctype="multipart/form-data" method="post">
                            Select a file: <input type="file" name="photo" id="photo" />   

                            <input type="submit" value="Upload" name="submit"/>
                        </form>
                    </noscript>


</div>

<div class="editor-field">
    <img src="<%: Model.Image.FileName %>" />
    <%: Html.TextBoxFor(model => model.Image.FileName) %>
    <%: Html.ValidationMessageFor(model => model.Image.FileName)%>
    <a href="#" onclick="jQuery('#imagedialog').dialog('open'); return false">Upload Image</a>
</div>

我在母版页上正确链接了 fileuploader.js 和 fileuploader.css，并且 uploader 显示正确，甚至调用了我的操作，但 HttpPostedFileBase 为 null 并且上传操作引发异常。关于我应该做什么有什么见解吗？

编辑

所以我发现使用 firebug 来发送 XmlHttpRequest。我该如何在上传操作中处理这个问题？

Answer 1

您在 Controller 操作中获得空参数的原因是因为此插件不发送 multipart/form-data向服务器请求。相反，它发送 application/octet-stream内容类型请求 header ，它将文件内容直接写入请求流，并附加参数 ?qqfile到包含文件名的 URL。因此，如果您想在 Controller 上检索此内容，您将需要直接读取流:

[HttpPost]
public ActionResult Upload(string qqfile)
{
    using (var reader = new BinaryReader(Request.InputStream))
    {
        // This will contain the uploaded file data and the qqfile the name
        byte[] file = reader.ReadBytes((int)Request.InputStream.Length);
    }
    return View();
}

如果您选择多个文件，插件只需向服务器发送多个请求，这样就可以工作。

此外，如果您想处理大于 int.MaxValue 的文件您必须从请求流中读取 block 并直接写入输出流，而不是将整个文件加载到内存缓冲区中:

using (var outputStream = File.Create(qqfile))
{
    const int chunkSize = 2 * 1024; // 2KB
    byte[] buffer = new byte[chunkSize];
    int bytesRead;
    while ((bytesRead = Request.InputStream.Read(buffer, 0, buffer.Length)) > 0)
    {
        outputStream.Write(buffer, 0, bytesRead);
    }
}

备注:删除createUploader来自您的 document.ready 的函数名称。那里应该是一个匿名函数。您甚至可以将其与 $(function() { ... }); 合并。您已经必须设置模式对话框。