根据输入数据更新Entity Framework中的行

Question

I have a very simple form. I am collecting Employee Name and DepartmentName from that form as shown below. I also have a hidden input which is named StatusID. Users are not able to see and enter any data in it. However i would like to update this StatusID based on data from DepartmentName input. Let say if DepartmentName is IT then i would like to insert "1" to StatusID row. If the departmentName is HR, StatusID will be updated as "2".

I tried many ways to achieve this but not able to do so.

Any idea how i can achieve it?

@using (Html.BeginForm()) {
@Html.AntiForgeryToken()
@Html.ValidationSummary(true)

<fieldset>
    <legend>Employee</legend>

    <div class="editor-label">
        @Html.LabelFor(model => model.Name)
    </div>
    <div class="editor-field">
        @Html.TextBoxFor(model => model.Name)
    </div>
    <div class="editor-label">
        @Html.LabelFor(model => model.DepartmentName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.DepartmentName)
    </div>

    <div class="editor-field">
        @Html.HiddenFor(model => model.StatusID)
    </div>
    <input type="submit" value="Create" />
 </fieldset>

And this is my controller for Create.

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create(Employee employee)
    {
        if (ModelState.IsValid)
        {
            db.Employee.Add(employee);
            db.SaveChanges();

            return RedirectToAction("Index");
        }

        return View(employee);
    }

And this is my Class:

  public partial class Employee
{
    public int EmployeeID { get; set; }
    public string Name { get; set; }
    public string DepartmentName{ get; set; }
    public int StatusID { get; set; }
}

Answer 1

您可以为其创建枚举，并根据部门的状态ID检查枚举条目，可以为此使用转换器

Answer 2

Is there a specific reason that you need to set StatusID in your view, can you not just do it as part of your controller method?

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(Employee employee)
{
    if (ModelState.IsValid)
    {
        switch (employee.DepartmentName)
        {
            case "IT":
                employee.StatusID = 1
                break;
            case "HR":
                employee.StatusID = 2
                break;
            default:
                employee.StatusID = 1
                break;
        }

        db.Employee.Add(employee);
        db.SaveChanges();

        return RedirectToAction("Index");
    }

    return View(employee);
}

Of course you can change from a switch statement to a ternary operator if you only ever want to check between values of 1 and 2

Answer 3

Thus StatusID depends on DepartmentName and this logic belongs to Employee class, you can set StatusID when setting DepartmentName :

private string deparmentName;

public string DepartmentName
{ 
   get { return deparmentName; }
   set 
   {
       deparmentName = value;

       switch(deparmentName)
       {
          case "IT" : StatusID = 1; break;
          case "HR" : StatusID = 2; break;
          default: 
              StatusID = 0; break;
       }
   }
}

Keep in mind, that user can input data not only in upper case. Consider also using enum for departments:

public enum Department
{
    None = 0,
    IT = 1,
    HR = 2
}

And use single property of this enum type instead of two properties for department name and status id:

public partial class Employee
{
    public int EmployeeID { get; set; }
    public string Name { get; set; }
    public Department Department { get; set; }
}

Answer 4

You could also define your own ModelBinder to map those properties the way you want :

public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        object model = bindingContext.Model;
        Employee employee = (Employee)model;
        if (employee == null)
        {
            employee = new Employee();
        }
        string departnementName = "DepartmentName";

        var departnementNameValue = bindingContext.ValueProvider.GetValue(departnementName);

        try
        {
            if (departnementName == "IT")
            {
                employee.StatusID = 1;
            }
        }
        catch (Exception ex)
        {
            bindingContext.ModelState.AddModelError(bindingContext.ModelName, ex.Message);
            bindingContext.ModelState.SetModelValue(departnementName, departnementNameValue);
        }
        return employee;
    }

Answer 5

If else or switch statement?

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(Employee employee)
{
    if (ModelState.IsValid)
    {
        if(employee.DepartmentName == "IT")
        {
           employee.StatusID == 1;
        }
        else if(employee.DepartmentName == "HR")
        {
           employee.StatusID == 2;
        }
        else
        {
           employee.StatusID == 1;
        }
        db.Employee.Add(employee);
        db.SaveChanges();            

        return RedirectToAction("Index");
    }

    return View(employee);
}