asp.net mvc-5 HttpPostedFileBase 为空

asp.net mvc-5 HttpPostedFileBase is null

我正在使用 asp.net mvc-5 HttpPostedFileBase 搞乱文件上传,但它显示我在选择图像后 HttpPostedFileBase 为空

这是我的代码

 <input type="file" title="search image" file-model="profileimage" id="allfilepath" name="file" />
 <button type="submit" class="btn btn-primary col-sm-5">
         <span class="glyphicon glyphicon-plus"></span>
 </button>

和我的控制器

    [HttpPost]
    public ActionResult insert(HttpPostedFileBase file, quotationcompany quotecomp)
    {
        var allowedExtensions = new[] {
        ".Jpg", ".png", ".jpg", "jpeg"
    };
        if (file == null)
        {
            ViewBag.message = "Please Select Image";
            return View();
        }
        else {
            ViewBag.message = "Image Uploaded Successfully";
            return View();
        }

    }

if (file == null)(on this line (file) is showing me null after i am uploading png image)

这段代码有什么问题?

检查表单属性

人们常犯的一个错误是在表单标记中遗漏了以下部分:

<form enctype="multipart/form-data">
</form>

同样在 MVC 中,您的表单结构可能看起来像这样

@using (Html.BeginForm("Action", "Controller", FormMethod.Post, new { @enctype = "multipart/form-data", @id = "myForm", @role="form" }))