Setting Default Value of DropDownList in MVC

Question

I've been looking around, and I can't quite find someone attempting to do quite what I am. I have several models that work together on a single page. The models are employees1, phone_manager, and phone_types.

I've managed to get insertion working just fine, but I can't seem to get the edit page to work. I need to take the currently stored phone_type which is a foreign key to phone_type_id and make it the default item in my combo box.

My model is:

[Table("employee.employees")]
public partial class employees1
{

    public employees1()
    {
        employee_email_manager = new List<email_manager>();
        employee_employment_history = new HashSet<employment_history>();
        employee_job_manager = new HashSet<job_manager>();
        employee_phone_manager = new HashSet<phone_manager>();
        this.salaries = new HashSet<salary>();
    }

    [Key]
    public int employee_id { get; set; }
    [Display(Name = "Employee ID")]
    public int? assigned_id { get; set; }

    [Display(Name = "Web User ID")]
    public int? all_id { get; set; }

    [Required]
    [StringLength(50)]
    [Display(Name = "First Name")]
    public string first_name { get; set; }

    [StringLength(50)]
    [Display(Name = "Last Name")]
    public string last_name { get; set; }

    [Column(TypeName = "date")]
    [Display(Name = "Birthday")]
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]
    public DateTime birth_day { get; set; }

    [Required]
    [StringLength(1)]
    [Display(Name = "Gender")]
    public string gender { get; set; }

    [Required]
    [StringLength(128)]
    [Display(Name = "Social")]
    public string social { get; set; }

    [Required]
    [StringLength(128)]
    [Display(Name = "Address")]
    public string address_line_1 { get; set; }

    [StringLength(50)]
    [Display(Name = "Suite/Apt#")]
    public string address_line_2 { get; set; }

    [Required]
    [StringLength(40)]
    [Display(Name = "City")]
    public string city { get; set; }

    [Required]
    [StringLength(20)]
    [Display(Name = "State")]
    public string state { get; set; }

    [Required]
    [StringLength(11)]
    [Display(Name = "Zip")]
    public string zip { get; set; }

    [Column(TypeName = "date")]
    [Display(Name = "Hire Date")]
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]
    public DateTime hire_date { get; set; }

    [Column(TypeName = "date")]
    [Display(Name = "Separation Date")]
    [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:MM/dd/yyyy}")]
    public DateTime? termination_date { get; set; }

    [StringLength(70)]
    [Display(Name = "Emergency Contact Name")]
    public string emergency_contact_name { get; set; }

    [StringLength(15)]
    [Display(Name = "Emergency Contact Number")]
    public string emergency_contact_phone { get; set; }

    [Display(Name = "Notes")]
    public string notes { get; set; }

    public virtual all_employees all_employees { get; set; }
    [Display(Name = "Email Addresses")]
    public virtual ICollection<email_manager> employee_email_manager { get; set; }
    [Display(Name = "Employment History")]
    public virtual ICollection<employment_history> employee_employment_history { get; set; }
    [Display(Name = "Position History")]
    public virtual ICollection<job_manager> employee_job_manager { get; set; }
    [Display(Name = "Phone Numbers")]
    public virtual ICollection<phone_manager> employee_phone_manager { get; set; }

    internal void CreatePhoneNumbers(int count = 1)
    {
        for (int i = 0; i < count; i++)
        {
            employee_phone_manager.Add(new phone_manager());
        }
    }

    [Table("employee.phone_manager")]
    public partial class phone_manager
    {
        /*public phone_manager()
        {
            phone_types = new HashSet<phone_types>();
        }*/

        [Key]
        public int phone_id { get; set; }

        public int employee_id { get; set; }

        [Required]
        [StringLength(15)]
        [Display(Name="Phone Number")]
        public string phone_number { get; set; }

        [StringLength(5)]
        [Display(Name = "Extension")]
        public string phone_extension { get; set; }

        [Display(Name = "Type")]
        public int phone_type { get; set; }

        [Column(TypeName = "date")]
        public DateTime date_added { get; set; }

        public bool deleted { get; set; }

        public virtual employees1 employees1 { get; set; }
        [ForeignKey("phone_type")]
        public virtual phone_types phone_types { get; set; }
        //public virtual ICollection<phone_types> phone_types { get; set; }
    }

    [Table("employee.phone_types")]
    public partial class phone_types
    {
        public phone_types()
        {
            phone_manager = new HashSet<phone_manager>();
        }

        [Key]
        public int phone_type_id { get; set; }

        [Required]
        [StringLength(50)]
        public string phone_type_name { get; set; }

        public virtual ICollection<phone_manager> phone_manager { get; set; }
    }
}

My Controller:

    public ActionResult Create()
    {
        ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id");
        var employee = new employees1();
        ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
        employee.CreatePhoneNumbers(1);
        return View(employee);
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes,employee_phone_manager")] employees1 employees1)
    {
        if (ModelState.IsValid)
        {
            foreach (employees1.phone_manager phone in employees1.employee_phone_manager.ToList())
            {
                if (phone.deleted == true)
                {
                    employees1.employee_phone_manager.Remove(phone);
                }
            }
            db.employees1.Add(employees1);
            db.SaveChanges();
            return RedirectToAction("Index");
        }
        var employee = new employees1();
        ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
        ViewBag.all = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
        return View(employees1);
    }

    // GET: /Employees/Edit/5
    public ActionResult Edit(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        employees1 employees1 = db.employees1.Find(id);
        if (employees1 == null)
        {
            return HttpNotFound();
        }
        var employee = new employees1();
        ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
        ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
        return View(employees1);
    }

    // POST: /Employees/Edit/5
    // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
    // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Edit([Bind(Include="employee_id,assigned_id,all_id,first_name,last_name,birth_day,gender,social,address_line_1,address_line_2,city,state,zip,hire_date,termination_date,emergency_contact_name,emergency_contact_phone,notes")] employees1 employees1)
    {
        if (ModelState.IsValid)
        {
            db.Entry(employees1).State = EntityState.Modified;
            db.SaveChanges();
            foreach (var item in employees1.employee_phone_manager)
            {
                db.Entry(item).State = EntityState.Modified;
                db.SaveChanges();
            }
            return RedirectToAction("Index");
        }
        var db2 = new LightHouseMain();
        var employee = new employees1();
        ViewBag.phone_type = new SelectList(db.phone_types, "phone_type_id", "phone_type_name");
        ViewBag.all_id = new SelectList(db.all_employees, "all_id", "all_id", employees1.all_id);
        return View(employees1);
    }

My View:

     @Html.LabelFor(x => x.phone_type)
    @Html.DropDownList("phone_type", string.Empty)
    @Html.LabelFor(x => x.phone_number)
    @Html.TextBoxFor(x => x.phone_number, new { @class = "phone", size = "10" })
    @Html.LabelFor(x => x.phone_extension)
    @Html.TextBoxFor(x => x.phone_extension, new { size = "4" })
    @Html.HiddenFor(x => x.date_added, new { @Value = System.DateTime.Now })
    @Html.HiddenFor(x => x.deleted, new { @class = "mark-for-delete" })
    @Html.RemoveLink("Remove", "div.phoneNumber", "input.mark-for-delete")

Any help is appreciated!

EDIT

Diagram:

Answer 1

A good practise is to not to use ViewBag. Try creating a simple model with properties that your current view needs.

You can also use SelectList(IEnumerable, String, String, Object) overload of SelectList where the object is the selected value. Just use this overload like this:

ViewBag.phonetype = new SelectList(db.phone_types, "phone_type_id", "phone_type_name", Model.phone_type );

Note: I have change ViewBag.phone_type to ViewBag.phonetype.

Answer 2

You probably need to do a bit more heavy lifting here.

Loop through the list to build the dropdown and set the selected value when you hit it.

Apologise if I've misread your data structure, but this is the theory:

Controller:

var phoneTypeList = new Dictionary<int, string>();
foreach (var pt in db.phone_types)
{
    phoneTypeList.Add(pt.phone_type_id, phone_type_name);

    if (pt.phone_type_id == employees1.phone_types.phone_type_id)
    {
         selectedValue = pt.phone_type_id;
    }
}

Then add phoneTypeList and selectedValue to viewmodel - or ViewBag if you like

View:

@Html.DropDownListFor(x => x.phone_type, new SelectList(Model.phoneTypeList, "Key", "Value", Model.selectedValue);

Answer 3

This sort of thing caused me hours of fun, especially when tackling the signatures for the DropDownListFor overloads

Anyway, the following will generate a drop down and select the value that is contained within the model.

@Html.DropDownListFor(x => x.phone_type, (SelectList)ViewBag.PhoneTypes)

If you wish, you can add a third argument, an anonymous object in the same way as the HiddenFor methods do, for styling purposes.