c# - MVC View 中未正确删除模型子对象

Question

我有一个基于主从模型的 MVC 主从 View 和每个详细记录的删除按钮。

按下删除按钮后，我发布要删除的 ID 和整个模型，我从模型中删除正确的详细记录并将其返回到 View 。

问题是 View 呈现不正确的详细记录。无论按下什么，它实际上都会删除最后一条记录。

模型

public class Customer
{
    public int ID { get; set; }
    [Required]
    public string Name { get; set; }
    public string Description { get; set; }

    public List<Contact> CustomerContacts { get; set; }
}
public class Contact
{
    public int ID { get; set; }
    public int CustomerID { get; set; }
    public string ContactName { get; set; }
    [Required]
    public string ContactEmail { get; set; }
}

Controller Action

    public ActionResult Index()
    {
        Customer customer = new Customer(){ ID=1, Name="CustOne", Description="Descr1"};

        Contact contact1 = new Contact() { ID = 1, CustomerID = 1, ContactName = "Cont_One", ContactEmail = "a@b.com" };
        Contact contact2 = new Contact() { ID = 2, CustomerID = 1, ContactName = "Cont_Two", ContactEmail = "b@c.com" };
        customer.CustomerContacts = new List<Contact>();
        customer.CustomerContacts.Add(contact1);
        customer.CustomerContacts.Add(contact2);

        return View(customer);
    }

    [HttpPost]
    public ActionResult Index(string btnSubmit, Customer customer)
    {
        int CustomerContactID = Convert.ToInt32(btnSubmit);

        if (!ModelState.IsValid)
        {
            return View(customer);
        }

        int indexOfCust = customer.CustomerContacts.FindIndex(c => c.ID == CustomerContactID);
        customer.CustomerContacts.RemoveAt(indexOfCust);

        return View(customer);
    }

View :

    @model MyMVCProblem.Models.Customer
@{
    ViewBag.Title = "Home Page";
}

<br />
@using (Html.BeginForm())
{
    <table>
        <tr>
            <td>Name</td>
            <td>
                @Html.TextBoxFor(m => m.Name)
                @Html.ValidationMessageFor(m => m.Name)
            </td>
        </tr>
        <tr>
            <td>Description</td>
            <td>
                @Html.TextAreaFor(m => m.Description)
            </td>
        </tr>
    </table>


    for (int i = 0; i < Model.CustomerContacts.Count; i++)
    {
        <table>
            <tr>
                <td>Contact Name</td>
                <td>
                    @Html.HiddenFor(m => m.CustomerContacts[i].ID)
                    @Html.TextBoxFor(m => m.CustomerContacts[i].ContactName)
                    @Html.ValidationMessageFor(m => m.CustomerContacts[i].ContactName)
                </td>
            </tr>
            <tr>
                <td>Contact e-mail</td>
                <td>
                    @Html.TextBoxFor(m => m.CustomerContacts[i].ContactEmail)
                    @Html.ValidationMessageFor(m => m.CustomerContacts[i].ContactEmail)
                </td>
            </tr>
        </table>
        <button type="submit" name="btnSubmit" id="Submit" value="@Model.CustomerContacts[i].ID">Delete</button>
        <br /><br />
    }
}

Answer 1

一种可能的解决方案是清除 ModelState。
示例如下:

[HttpPost]
    public ActionResult Index(string btnSubmit, Customer customer)
    {
        int CustomerContactID = Convert.ToInt32(btnSubmit);

        if (!ModelState.IsValid)
        {
            return View(customer);
        }

        int indexOfCust = customer.CustomerContacts.FindIndex(c => c.ID == CustomerContactID);
        customer.CustomerContacts.RemoveAt(indexOfCust);
        ModelState.Clear();
        return View(customer);
    }