Question

我对删除操作有以下操作：

[HttpPost]
public ActionResult Delete(int id, EmployeeDeleteViewModel collection)
{
    try
    {
        if (ModelState.IsValid)
        {
            Employee e = new Employee 
            { 
                EmpId = collection.EmpID, 
                FirstName = collection.FirstName, 
                LastName = collection.LastName, 
                DepartmentId = collection.DepartmentID 
            };

            db.Employees.Remove(e);
            db.SaveChanges();
            return RedirectToAction("Index", new { id = id });
        }

        // TODO: Add update logic here

        return View(collection);
    }
    catch
    {
        return View();
    }
}

删除视图是：

@model VirtualCampus2.Models.EmployeeDeleteViewModel

@{
    ViewBag.Title = "Delete";
}

<h2>Delete</h2>

<h3>Are you sure you want to delete this?</h3>

<fieldset>
    <legend>EmployeeDeleteViewModel</legend>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.EmpID)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.EmpID)
    </div>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.FirstName)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.FirstName)
    </div>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.LastName)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.LastName)
    </div>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.DepartmentName)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.DepartmentName)
    </div>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.DepartmentID)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.DepartmentID)
    </div>
</fieldset>
@using (Html.BeginForm())
{
    <p>
        <input type="submit" value="Delete" /> |
        @Html.ActionLink("Back to List", "Index")
    </p>
}

当我在删除视图上单击“删除”时，会发生以下错误：

到action方法的第二个参数＆＃34; collection＆＃34;，它会在其属性中发送一个零和null的集合
不会删除记录

这是video that shows the problem

为什么会发生这种情况，我该如何解决这个问题？

史蒂夫：我通过创建单独的视图模型和删除操作来进行更改：

视图模型：

public class EmpDeleteCommitViewModel
{
    public int EmpID { get; set; }
}

操作删除方法：

        [HttpGet]//this works fine, gets the record to show on view
        public ActionResult Delete(int id)
        {
            var empList = db.Employees.ToList();

            var employee = empList.Where(e => e.EmpId == id).Select(e => new EmployeeDeleteViewModel 
            {
                EmpID=e.EmpId, 
                FirstName= e.FirstName, 
                LastName=e.LastName, 
                DepartmentID=e.DepartmentId,
                DepartmentName=e.Department.Name
            }).FirstOrDefault();

            return View(employee);
        }        



[HttpPost] //BUT THIS DOES NOT WORK!, evm EmpID does not contain id value
public ActionResult Delete(EmpDeleteCommitViewModel evm)
        {
            try
            {
                var employee = db.Employees.Where(e => e.EmpId == evm.EmpID).FirstOrDefault();
                db.Employees.Remove(employee);
                db.SaveChanges();
                return RedirectToAction("Index", new { id = evm.EmpID });

            }
            catch
            {
                return View();
            }
        }

Answer 1

表单标记之间没有表单控件（<input>），因此在提交表单时没有任何内容可以回发。您所做的只是生成一些文本来显示属性值。

您无需在方法中包含EmployeeDeleteViewModel collection参数。假设您使用正确的路由，您的int id参数将与员工的id绑定，因此您需要根据id和数据库从数据库中获取原始数据模型。然后删除它。

为什么删除未能删除记录？

1 个答案: