Get DropDownListFor selected value in multiple model - asp.net

Question

I create multiple model
public class MultipleModel
{
public Photo Photo { get; set; }
public Room Room { get; set; }
}
for two different models:
public class Room
{
public int Id { get; set; }
public string NumberRoom { get; set; }
public virtual ICollection<Photo> Photo { get; set; }
}
public class Photo
{
public int Id { get; set; }
public string PhotoName { get; set; }
public int Roomid { get; set; }
public virtual Room Room { get; set; }
}
On click Submit in my view i want upload image to the folder with the name from DropDownListFor selected item ( for example /images/2/, where 2=id from DropDownListFor) and add to database. How i can correctly send selected item from DropDownListFor using Html.BeginForm?
My view:
#using Hotel.BusinessObject
#model MultipleModel
#using (Html.BeginForm("AddRoomImg", "Admin",
FormMethod.Post, new { enctype = "multipart/form-data", id = Model.Room.Id}))
{
<div>#Html.DropDownListFor(m=> m.Room.Id, ViewBag.roomlist as SelectList, "Select Room")</div>
<input type="file" name="img" />
<input type="submit" value="upload" />
}
And my controller, where Room.Id in formCollection is always=0 and int? id not works and return NULL
public ActionResult AddRoomImg()
{
ViewBag.roomlist = new SelectList(db.Room, "Id", "NumberRoom");
return View();
}
[HttpPost]
public ActionResult AddRoomImg(FormCollection formCollection, int? id)
{
foreach (string item in Request.Files)
{
HttpPostedFileBase file = Request.Files[item] as HttpPostedFileBase;
if (file.ContentLength == 0)
continue;
if (file.ContentLength > 0)
{
ImageUpload imageUpload = new ImageUpload { Width = 600 };
ImageResult imageResult = imageUpload.RenameUploadFile(file);
if (imageResult.Success)
{
//TODO: write the filename to the db
}
else
{
ViewBag.Error = imageResult.ErrorMessage;
}
}
}

Answer 1

Try this
[HttpPost]
public ActionResult AddRoomImg(MultipleModel model, HttpPostedFileBase img)
{
//your code here
}
or
[HttpPost]
public ActionResult AddRoomImg(MultipleModel model)
{
var image = Request.Files(0); //access your images
//rest of your code here
}

Answer 2

As your question is about getting selected value from dropdownListFor into the MultipleModel, first of all you should update your function parameters.
use MultipleModel model to get the form data into model andHttpPostedFileBase img instead of FormCollection formCollection to get the image file as object. try the following way.
[HttpPost]
public ActionResult AddRoomImg(MultipleModel model, HttpPostedFileBase img)
{
// To get the selected value from dropdownListFor
var selectedRoomId = model.Room.Id;
// do what you want to do with img object
// you will get img.name in the file object that you can rename
}