我想更新我的產(chǎn)品實(shí)體，但每當(dāng)我提交表單時(shí)，它都會(huì)拋出：System.InvalidOperationException：“序列不包含任何元素”這是我的觀點(diǎn)：@model myadminpanel.Models.product@using (Html.BeginForm()){    <div class="container">        <div class="form-group">            <label>ProductName</label>            @Html.TextBoxFor(x => x.ProductName, new { @class = "form-control" });        </div>        <div class="form-group">            <label>ProductDescription</label>            @Html.TextBoxFor(x => x.ProductDescription, new { @class = "form-control" });        </div>        <div class="form-group">                    <label>Price</label>            @Html.TextBoxFor(x => x.Price, new { @class = "form-control" });        </div>        <div class="form-group">            <label>Quantity</label>            @Html.TextBoxFor(x => x.Quantity, new { @class = "form-control" });        <div class="button">                    <button>Submit</button>                </div>            </div>}我的控制器編輯代碼是這樣的：public ActionResult ProductEdit(int id){    var item = db.products.Where(x => x.ProductID == id).First();    return View(item);}[HttpPost]public ActionResult ProductEdit(product model){    var item = db.products.Where(x => x.ProductID == model.ProductID).First();    item.ProductName= model.ProductName;    item.ProductDescription = model.ProductDescription;    item.Price = model.Price;    item.Quantity = model.Quantity;    db.SaveChanges();    return View();}這是我的產(chǎn)品模型：namespace myadminpanel.Models{    using System;    using System.Collections.Generic;    public partial class product    {        public int ProductID { get; set; }        public string ProductName { get; set; }        public string ProductDescription { get; set; }        public Nullable<decimal> Price { get; set; }        public Nullable<int> Quantity { get; set; }        public string CategoryName { get; set; }        public Nullable<int> CategoryID { get; set; }        public virtual category category { get; set; }    }}