ASP.NET MVC多上传控件场景下无法向服务器提交数据问题

我使用Telerik控件构建了如下表单用于向服务器提交数据，但当上传文件达到一定大小后，服务器无法正常处理该请求。我已在配置文件中添加了请求大小限制相关设置，但问题仍未解决。

前端视图代码（Razor + JavaScript） #

@using (Html.BeginForm("Add", "Storage", FormMethod.Post, new { @id = "frmItem", @class = "form", enctype = "multipart/form-data" }))
{
<table class="table table-bordered">
    <thead class="bg-dark text-center text-white">
        <tr>
            <th colspan="2">Add/Modify Item</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td style="width:404px;">Item ID Name</td>
            <td>
                @(Html.Kendo().TextBox().Name("ItemName")
        .HtmlAttributes(new { placeholder = "Item ID Name", required = "required", validationmessage = "Enter Item ID Name" }))
            </td>
        </tr>
        <tr>
            <td>UN Number</td>
            <td>
                @(Html.Kendo().TextBox().Name("UnNumber")
        .HtmlAttributes(new { placeholder = "UN Number", required = "required", validationmessage = "Enter UN Number" }))
            </td>
        </tr>
        <tr>
            <td>Packing Instructions</td>
            <td>
                @(Html.Kendo().TextBox().Name("PackingInstructions")
        .HtmlAttributes(new { placeholder = "Packing Instructions", required = "required", validationmessage = "Enter Packing Instructions" }))
            </td>
        </tr>
        <tr>
            <td>SDS Sheet</td>
            <td>
                @(Html.Kendo().Upload().Name("SdsSheet")
        .Multiple(false))
            </td>
        </tr>
        <tr>
            <td>Cargo Only?</td>
            <td>@(Html.Kendo().CheckBox().Name("Cargo"))</td>
        </tr>
        <tr>
            <td>Example Shipment Ground (Fully Regulated)</td>
            <td>@(Html.Kendo().Upload().Name("GroundShipment"))</td>
        </tr>
        <tr>
            <td>Example Shipment Next Day Air (Fully Regulated)</td>
            <td>@(Html.Kendo().Upload().Name("NextDayShipment"))</td>
        </tr>
        <tr>
            <td>Example Shipment Freight (Fully Regulated)</td>
            <td>@(Html.Kendo().Upload().Name("FreightShipment"))</td>
        </tr>
        <tr>
            <td>Example Shipment Ground (Limited Quantity)</td>
            <td>@(Html.Kendo().Upload().Name("GroundShipmentLimited"))</td>
        </tr>
        <tr>
            <td>Example Shipment Next Day Air (Limited Quantity)</td>
            <td>@(Html.Kendo().Upload().Name("NextDayShipmentLimited"))</td>
        </tr>
        <tr>
            <td>Example Shipment Freight (Limited Quantity)</td>
            <td>@(Html.Kendo().Upload().Name("FreightShipmentLimited"))</td>
        </tr>
        <tr>
            <td colspan="2">
                <button id="btnSubmit" class="k-button k-button-solid-primary k-button-solid k-button-md k-rounded-md" type="button">Submit</button>
                @Html.ActionLink("Download", "GetReport", new { controller = "Storage" }, new { target = "_blank" })
            </td>
        </tr>
    </tbody>
</table>
}
 <script>
$(function () {
    $("#btnSubmit").on("click", function () {
       var validator = $("#frmItem").kendoValidator().data("kendoValidator");
        if (validator.validate()) {
            var formdata = new FormData($('#frmItem').get(0));
            showSpinner();
            let url = "/Storage/Add/";
            $.ajax({
                url: url,
                type: 'POST',
                data: formdata,
                dataType: 'json',
                contentType: false,
                processData: false,
                success: function (result) {
                    if (result === "OK") {
                        hideSpinner();
                        swal(
                            'Item submitted',
                            'Item saved successfully',
                            'success',
                            5000
                        ).then(function () {
                            window.location.reload();
                        });
                    }
                    else {
                        swal(
                            'Error',
                            'An internal error occurred. Please retry',
                            'error'
                        ).then(function () {
                        });
                        hideSpinner();
                    }
                }
            });
        }
    });
});
</script>

控制器处理方法 #

[HttpPost]
public JsonResult Add(HazMatItemModel itemModel)
{
    ItemRepository itemRepository = new ItemRepository();
    itemModel.FolderPath = "~Uploads/";

    if (itemRepository.AddUpdateItem(itemModel))
       return new JsonResult { Data = "OK" };

    return new JsonResult { Data = "Error" };
 }

Web.config配置设置 #

<system.web>
    <httpRuntime targetFramework="4.7.2" maxRequestLength="2147483647" executionTimeout="1600" requestLengthDiskThreshold="2147483647" />
</system.web>
<system.webServer>
    <security>
        <requestFiltering>
            <requestLimits maxAllowedContentLength="2147483647" />
            <!--50MB-->
        </requestFiltering>
    </security>
</system.webServer>

模型类代码 #

using System.ComponentModel.DataAnnotations;
using System.Web;

namespace HazMat.Models
{
public class HazMatItemModel : BaseEntity
{
    public int ItemId { get; set; }
    [Required]
    public string ItemName { get; set; }
    [Required]
    public string UnNumber { get; set; }
    [Required]
    public string PackingInstructions { get; set; }
    public string FolderPath { get; set; }
    public HttpPostedFileBase SdsSheet { get; set; }
    public string SdsSheetFileName { get; set; }
    public bool IsCargo { get; set; }
    public HttpPostedFileBase GroundShipment { get; set; }
    public string GroundShipmentFileName { get; set; }
    public HttpPostedFileBase NextDayShipment { get; set; }
    public string NextDayShipmentFileName { get; set; }
    public HttpPostedFileBase FreightShipment { get; set; }
    public string FreightShipmentFileName { get; set; }
    public HttpPostedFileBase GroundShipmentLimited { get; set; }
    public string GroundShipmentLimitedFileName { get; set; }
    public HttpPostedFileBase NextDayShipmentLimited { get; set; }
    public string NextDayShipmentLimitedFileName { get; set; }
    public HttpPostedFileBase FreightShipmentLimited { get; set; }
    public string FreightShipmentLimitedFileName { get; set; }
  }
}

解决方案排查步骤 #

• 确认配置生效范围：检查web.config中的设置是否放在正确位置，若应用有子目录或虚拟目录，需确保配置覆盖目标站点；注意maxAllowedContentLength单位是字节，当前配置为2GB，与注释的50MB不符，可调整为52428800（50MB）匹配需求。

• 检查模型绑定与文件处理逻辑：验证ItemRepository.AddUpdateItem方法是否存在文件大小限制，或处理文件时是否抛出IO异常（如磁盘空间不足、权限不足）。可在控制器中添加日志，输出itemModel中各文件属性的状态，确认文件是否被正确接收。

• 调整IIS站点级配置：打开IIS管理器，进入目标站点的“请求筛选”功能，检查“最大允许内容长度”是否与web.config配置一致，避免站点级配置覆盖全局设置。

• 增加AJAX请求超时：大文件上传耗时较长，需在AJAX请求中添加超时设置，避免请求因超时中断：

  $.ajax({
      // 原有配置
      timeout: 300000 // 设置为5分钟，根据实际情况调整
  });
  

• 检查应用程序池设置：确认IIS应用程序池的“队列长度”足够大，关闭不必要的自动回收规则，避免大文件上传过程中应用池被回收。

• 启用详细错误日志：在web.config中开启详细错误输出，捕获具体异常信息：

  <system.web>
      <customErrors mode="Off"/>
  </system.web>
  <system.webServer>
      <httpErrors errorMode="Detailed"/>
  </system.webServer>
  

内容的提问来源于stack exchange，提问作者Developer