Question

我有一个带ActionResult编辑的LaptopController。我在asp.net mvc中创建了一个编辑剃刀视图。但是当我编辑时，它返回一个异常

这是控制器的代码

   [HttpGet]
    public ActionResult Edit(int id)
    {

        LAPTOP laptop = data.LAPTOPs.SingleOrDefault(n => n.ID == id);
        if (laptop == null)
        {
            Response.StatusCode = 404;
            return null;
        }



        ViewBag.IDM = new SelectList(data.manufacturers.ToList().OrderBy(n => n.ManufacturerName), "IDM", "ManufacturerName", laptop.IDM);
        return View(laptop);
    }

    [HttpPost]
    [ValidateInput(false)]

    public ActionResult SuaSP(LAPTOP laptop, HttpPostedFileBase fileUpload)
    {

        ViewBag.IDM = new SelectList(data.manufacturers.ToList().OrderBy(n => n.ManufacturerName), "IDM", "ManufacturerName");



        var fileName = Path.GetFileName(fileUpload.FileName);
        var path = Path.Combine(Server.MapPath("~/Images"), fileName);
        fileUpload.SaveAs(path);
        laptop.ImageCover = fileName;
        //UpdateModel(laptop);
        data.SubmitChanges();

        return RedirectToAction("Laptop");
    }

导致异常的行是：

 var fileName = Path.GetFileName(fileUpload.FileName);

当我调试它时，告诉我fileName为空

这是用于编辑的代码：

@model GoodLaptop.Models.LAPTOP

@using（Html.BeginForm（new {enctype =“ multipart / form-data”}） {

@Html.AntiForgeryToken()

<div class="form-horizontal">
    <h4>Laptop</h4>
    <hr />
    @Html.ValidationSummary(true, "", new { @class = "text-danger" })
    @Html.HiddenFor(model => model.ID)

    <div class="form-group">
        @Html.LabelFor(model => model.ProductName, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.ProductName, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.ProductName, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Price, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Price, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Price, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.ImageCover, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            Chọn ảnh mới
            <input type="file" name="fileUpload" />
            <img src="@Url.Content("~/Images/"+ Model.ImageCover)" width="120" />(Ảnh hiện tại)
            @ViewBag.Thongbao
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.UpdateDate, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.UpdateDate, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.UpdateDate, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Amount, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Amount, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Amount, "", new { @class = "text-danger" })
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.IDM, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.DropDownList("IDM")
        </div>
    </div>

    <div class="form-group">
        <div class="col-md-offset-2 col-md-10">
            <input type="submit" value="Save" class="btn btn-default" />
        </div>
    </div>
</div>

}

请帮助，非常感谢

Answer 1

您当前正在错误使用@Html.BeginForm()辅助函数：

@using (Html.BeginForm(new { enctype = "multipart/form-data" }))
{
    // form contents
}

此定义与以下重载匹配：

public static MvcForm BeginForm(
    this HtmlHelper htmlHelper,
    object routeValues
)

由于您将enctype定义为routeValues参数，因此enctype标签的<form> HTML属性仍未设置为multipart/form-data和{{1 }}仍包含空值。您应该改用此重载：

HttpPostedFileBase

您的public static MvcForm BeginForm( this HtmlHelper htmlHelper, string actionName, string controllerName, FormMethod method, object htmlAttributes )助手将成为此助手，因为您已将控制器操作标记为@Html.BeginForm()：

[HttpPost]

'你调用的对象是空的。' ASP.net MVC使用数据库中的图像进行编辑

1 个答案: