从MVC中的另一个模型下拉列表绑定

Question

我是asp.net mvc的新手

我在两个表中都有两个表tblEmployee和tblDepartment，常见字段是部门ID。 如果用户创建新员工，他们必须从tblDepartment表中选择他们的部门列表。我从该表中获得部门列表没有问题，但是当我提交表单时，离开的部分将无效进入数据库。

模型

public partial class Department
{
    public Department()
    {
        this.tblEmployees = new HashSet<Employee>();
    }
    public int Id { get; set; }
    public string Name { get; set; }
    public virtual ICollection<Employee> tblEmployees { get; set; }
    public Employee employee { get; set; }
}

public partial class Employee
{
    public int EmployeeId { get; set; }
    public string Name { get; set; }
    public string Gender { get; set; }
    public string City { get; set; }
    public Nullable<int> DepartmentId { get; set; }

    public virtual Department tblDepartment { get; set; }
    public List<Department> deprtment { get; set; }
    public virtual string Department { get; set; }
    public bool available { get; set; }
}

控制器：

public ActionResult Create()
{
    SampleDbContext Db = new SampleDbContext();
    List<Employee> employees = Db.Employees.Include("tblDepartment").ToList();
    ViewBag.list = new SelectList(Db.Departments, "Id", "Name");

    return View();
}

[HttpPost]
public ActionResult Create( Employee employee)
{
    SampleDbContext Db = new SampleDbContext();
    if (ModelState.IsValid)
    {
        Db.Employees.Add(employee);
        Db.SaveChanges();
        return RedirectToAction("Index");
    }
    return View(employee);
}

查看：

@model EmployeeList.Models.Employee
....  
@using (Html.BeginForm()) 
{
    @Html.AntiForgeryToken()
    <div class="form-horizontal">
        <h4>Employee</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
            </div>
        </div>
        .... // controls for other properties of Employee
        <div class="form-group">
            @Html.LabelFor(model => model.DepartmentId, "DepartmentId", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("list","select Depar")
                @Html.ValidationMessageFor(model => model.DepartmentId, "", new { @class = "text-danger" })
            </div>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}