c# - MVC HttpPostedFileBase 始终为空

Question

我有这个 Controller ，我想做的是将图像作为 [byte] 发送到 Controller ，这是我的 Controller :

[HttpPost]
public ActionResult AddEquipment(Product product, HttpPostedFileBase image) 
 {

            if (image != null) 
            {
                product.ImageMimeType = image.ContentType;
                product.ImageData = new byte[image.ContentLength];
                image.InputStream.Read(product.ImageData, 0, image.ContentLength);
            }

            _db.Products.Add(product);
            _db.SaveChanges();

            return View();
 }

在我看来:

@using (Html.BeginForm("AddEquipment", "Equipment", FormMethod.Post)) {

    <fieldset>
        <legend>Product</legend>

        <div class="editor-label">
            @Html.LabelFor(model => model.Name)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Name)
            @Html.ValidationMessageFor(model => model.Name)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Description)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Description)
            @Html.ValidationMessageFor(model => model.Description)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Price)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Price)
            @Html.ValidationMessageFor(model => model.Price)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Category)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Category)
            @Html.ValidationMessageFor(model => model.Category)
        </div>

        <div>
        <div>IMAGE</div>
        <input type="file" name="image" />

        </div>


        <p>
            <input type="submit" value="Create" />
        </p>
    </fieldset>
}

但问题是在我的 Controller 上图像的值总是空的，我似乎无法获得关于 HttpPostedFileBase 的任何信息

Answer 1

您需要使用 multipart/form-data 添加 encType。

@using (Html.BeginForm("AddEquipment", "Equipment", FormMethod.Post, new {enctype = "multipart/form-data" })) {

如果它是一个 ViewModel，您也可以随时将它添加到您的模型中，如下所示:

public class Product 
{
    public Product()
    {
        Files = new List<HttpPostedFileBase>();
    }

    public List<HttpPostedFileBase> Files { get; set; }
    // Rest of model details
}

您可以通过删除不需要的参数来检索文件，即

[HttpPost]
public ActionResult AddEquipment(Product product) 
 {
    var file = model.Files[0];
    ...
 }