Question

我试图使用此处提到的示例How to do a ASP.NET MVC Ajax form post with multipart/form-data?

但我一直收到“失败”错误消息框

Index.cshtml

<script src="~/Scripts/jquery-1.8.2.min.js"></script>
<script src="~/Scripts/jquery.unobtrusive-ajax.min.js"></script>
<h2>Files Upload</h2>
<script type="text/javascript">
$(function() {
    $("#form0").submit(function(event) {
        var dataString;
        event.preventDefault();
        var action = $("#form0").attr("action");
        if ($("#form0").attr("enctype") == "multipart/form-data") {
            //this only works in some browsers.
            //purpose? to submit files over ajax. because screw iframes.
            //also, we need to call .get(0) on the jQuery element to turn it into a regular DOM element so that FormData can use it.
            dataString = new FormData($("#form0").get(0));
            contentType = false;
            processData = false;
        } else {
            // regular form, do your own thing if you need it
        }
        $.ajax({
            type: "POST",
            url: action,
            data: dataString,
            dataType: "json", //change to your own, else read my note above on enabling the JsonValueProviderFactory in MVC
            contentType: contentType,
            processData: processData,
            success: function(data) {
                //BTW, data is one of the worst names you can make for a variable

            },
            error: function(jqXHR, textStatus, errorThrown) {
                //do your own thing
                alert("fail");
            }
        });
    }); //end .submit()
});
</script>
<div id="uploadDiv">
@Html.Action("Files", "Home")
</div>

@using (Ajax.BeginForm("Files", "Home", new AjaxOptions { UpdateTargetId = "uploadDiv", HttpMethod = "Post" }, new { enctype = "multipart/form-data", @id="form0"}))
{
<div>
    <div>Upload new file:
        <input type="file" name="file" /></div>
    <input type="submit" value="Save" />
</div>
}
<br />

控制器

public PartialViewResult Files(HttpPostedFileBase file)
    {
        IEnumerable<string> files;
        if ((file != null) && (file.ContentLength > 0))
        {
            string fileName = file.FileName;
            string saveLocation = @"D:\Files";
            string fullFilePath = Path.Combine(saveLocation, fileName);               


            try
            {
                file.SaveAs(fullFilePath);
                FileInfo fileInfo = new FileInfo(fullFilePath);
                file.InputStream.Read(new byte[fileInfo.Length], 0, file.ContentLength);                    
            }
            catch (Exception e)
            {
                TempData["FileUpload"] = e.Message;
                return PartialView();
            }
            files = Directory.GetFiles(@"D:\Files\");
            return PartialView(files);
        }
        else
        {
            files = Directory.GetFiles(@"D:\Files\");
            return PartialView(files);
        }
    }

Files.cshtml

@model IEnumerable<string>

@foreach (string f in Model)
{
<p>@f</p>
}

Global.asax中

ValueProviderFactories.Factories.Add(new JsonValueProviderFactory());

Answer 1

这更复杂，更好地使用jquery forms plugin。

以下是样本：

<强> Html.BeginForm

 @using (Html.BeginForm("YourAction", "YourController"))
{
    @Html.AntiForgeryToken()
    <input type="file" name="files"><br>
    <input type="submit" value="Upload File to Server">
}

行动方法

    [HttpPost]
    [ValidateAntiForgeryToken]
    public void YourAction(IEnumerable<HttpPostedFileBase> files)
    {
        if (files != null)
        {
            foreach (var file in files)
            {
                // Verify that the user selected a file
                if (file != null && file.ContentLength > 0)
                {
                    // extract only the fielname
                    var fileName = Path.GetFileName(file.FileName);
                    // TODO: need to define destination
                    var path = Path.Combine(Server.MapPath("~/Upload"), fileName);
                    file.SaveAs(path);
                }
            }
        }
    }

进度条

<div class="progress progress-striped">
   <div class="progress-bar progress-bar-success">0%</div>
</div>

Jquery＆amp;表格脚本

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7/jquery.js"></script>
<script src="http://malsup.github.com/jquery.form.js"></script>

<script>
(function() {

var bar = $('.progress-bar');
var percent = $('.progress-bar');
var status = $('#status');

$('form').ajaxForm({
    beforeSend: function() {
        status.empty();
        var percentVal = '0%';
        bar.width(percentVal)
        percent.html(percentVal);
    },
    uploadProgress: function(event, position, total, percentComplete) {
        var percentVal = percentComplete + '%';
        bar.width(percentVal)
        percent.html(percentVal);
    },
    success: function() {
        var percentVal = '100%';
        bar.width(percentVal)
        percent.html(percentVal);
    },
    complete: function(xhr) {
        status.html(xhr.responseText);
    }
}); 

})();       
</script>

<强>更新...

两次调用动作方法问题的人是由于Ajax.BeginForm，只需将其转换为Html.BeginForm（）。 有关更多说明和下载示例代码，请参阅this blog 。

Answer 2

来自Ashwini Verma的答案几乎是正确的，但它有一个缺点，表单已提交两次。

这是由使用Ajax.BeginForm()引起的。使用Html.BeginForm()将解决此问题。

以下是一个例子：

@* do not use Ajax.BeginForm() as it would cause the form to submit twice in connection with jQuery.Form *@
@using (var lForm = Html.BeginForm( 
  <ActionName>, <ControllerName>, FormMethod.Post, 
  new Dictionary<string, object> {{"name", <YourFormName>}, {"enctype", "multipart/form-data"}}))
{

Answer 3

您需要html5文件处理并在客户端上读取文件内容以获取base64编码数据。

在客户端，你必须把：

<div>
        @Html.HiddenFor(m => m.AttachmentFileName)
        @Html.HiddenFor(m => m.AttachmentFileSize)
        @Html.HiddenFor(m => m.AttachmentFileType)
        @Html.HiddenFor(m => m.AttachmentFileContentsBase64)

    <input type="file" name="AttachmentFile" id="AttachmentFile" onchange="handleAttachmentFileChange(this.files)" />
    @Html.ValidationMessageFor(m => m.AttachmentFile)
</div>

<script>
    function handleAttachmentFileChange(files) {
        var file = files[0];
        $("#AttachmentFileName").val(file.name);
        $("#AttachmentFileSize").val(file.size);
        $("#AttachmentFileType").val(file.type || "application/octet-stream");

        var fileReader = new FileReader();
        fileReader.onload = function () {
            fileReader.result;

            $("#AttachmentFileContentsBase64").val(fileReader.result);
        };
        fileReader.readAsDataURL(file);
    };
</script>

因此，您的代码将使用文件数据（文件名，类型，大小，base64编码内容）填充隐藏字段。在服务器端你输入：

            if (AttachmentFileSize > 0)
            {
                string fileName = AttachmentFileName.Contains("\\") ? AttachmentFileName.Substring(AttachmentFileName.LastIndexOf("\\") + 1) : AttachmentFileName;

                byte[] fileBytes = Convert.FromBase64String(AttachmentFileContentsBase64.Substring(AttachmentFileContentsBase64.IndexOf(',') + 1));

//save file to file system or db

                ModelState.Remove("CurrentAttachmentFileId");
                ModelState.Remove("CurrentAttachmentFileName");

            }
            else if (AttachmentFileSize == -1)
            {
//remove existing file from fs or db
            }

代码需要使用您的模型和逻辑进行修改，但它对我有用

在MVC中使用Ajax.BeginForm上传文件

3 个答案: