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C# MVC Post form not passing ID from view to controller

I am new to MVC. I work on an auction application. On the auction site, there should be a form for making a bid. I have a problem passing the auction parameter to the controller
My models:
public class Auctions
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int ID { get; set; }
public string title { get; set; }
(..) some other fields
public List<Bid> bids = new List<Bid>();
}
public class BiddingViewModel
{
public Auctions auctionToSend { get; set; }
public double bid { get; set; }
}
My view:
#model BiddingViewModel
#using(Html.BeginForm("CreateBid", "Auction", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
#Html.HiddenFor(model=>model.auctionToSend)
#Html.EditorFor(model => model.bid)
<input type="submit" value="Make it work" />
}
and my controller:
[AllowAnonymous]
public ActionResult AuctionPage(int id)
{
var tmp = _context.Auctions.FirstOrDefault(i => i.ID == id);
BiddingViewModel bvm = new BiddingViewModel
{
auctionToSend = tmp,
bid = -1
};
return View(bvm);
}
[Authorize]
[HttpPost]
public async Task<ActionResult> CreateBid(BiddingViewModel bvm)
{
//After filling the form from view, the bvm.auctionToSend is null, whereas the bvm.bid value is visible
return RedirectToAction("AuctionList", "Auction");
}
My problem is that the auction data (perfectly visible in the view) is not sent back to the controller. I checked the internet and it showed me some naming-conflicts' solutions, so I made sure the naming is different, but this didn't fix my problem.

auctionToSend is a complex object and your use of #Html.HiddenFor(model=>model.auctionToSend) is generating
<input type="hidden" name="auctionToSend" value="yourAssembly.Auctions" ... />
If you just need the ID of the Auctions, then use
#Html.HiddenFor(m => m.auctionToSend.ID)
otherwise you need to generate a hidden input for each property of Auctions but that would be inefficient, particularly as Auctions contains a property which is a collection, so if you need the Auctions object in the POST method, better to just get it again based on the ID value your submitting.
As a side note, you really should be using a view model with just properties for the double Bid and int AuctionID

Form submission in partial views in MVC

I am developing a simple mvc application . The code is as follows:
Model .cs:
public class CustomModel
{
public IEnumerable<lang> lstlang { get; set; }
public IEnumerable<org> lstOrg { get; set; }
}
public class lang
{
public int langid { get; set; }
public string langName { get; set; }
}
public class org
{
public int orgId { get ;set;}
public string orgName { get; set; }
}
Controller.cs
public Action Index()
{
// Get data from database and fill the model
var model = new CustomModel();
return View(model);
}
public Action Partial()
{
// Get data from database and fill the model
var model = new CustomModel();
return PartialView(model);
}
[HttpPost]
public Action Partial(FormCollection frm, CustomModel model)
{
// Get data from database and fill the model
var model = new CustomModel();
return PartialView(model);
}
Index.cshtml
#model CustomModel
#Html.TextboxFor(x => x.lang.FirstOrDefault().id);
<input type="button" id="btn" />
#Html.RenderPartial("Partial", model)
Partial.cshtml
#model CustomModel
#Html.TextboxFor(x => x.lang.FirstOrDefault().id);
<input type="submit" id="submit" />
The thing is, when I click the submit button in the Partial.cshtml page, and examine the model in httppost method in public Action Partial(FormCollection frm, CustomModel model), the model contains null for both lists lstlang and lstOrg, but the formcollection[0] will give the selected textbox value.
What am I missing, or is this the right way of using partial views?

Don't use FirstOrDefault(). If you want to post something back to the front end with collections, you'll need to use indexing.
Public class CustomModel
{
public ICollection<lang> lstlang { get; set; }
public ICollection<org> lstOrg { get; set; }
}
#HTML.textboxfor(x=>x.lang[0].id);

ASP.NET MVC Passing action parameter to the view

Let's say that I have a Action method like this:
public ActionResult Page(int? id)
{
}
The question is, how can I read 'id' parameter in View?

Your code won't build successfully, until you return a view like this
public ActionResult Page(int? id)
{
return View();
}
and because you want to return id to your view you can do
Simple object
public ActionResult Page(int? id)
{
return View(id);
}
Just remember to accept the new value in your view, by dong the following at the top (very first line)
#model int?
ViewModel approach
public class MyViewModel
{
public int? Id { get; set; }
//Other properties here
}
public ActionResult Page(int? id)
{
var myViewModel = new MyViewModel()
{
Id = id
};
return View(myViewModel);
}
and then in your view
#model MyViewModel

You can access parameters from Request in view as below
Request.Params["id"]

complex model stays null after post

My question is related to this question and answer
The following complex model:
public class EditSubmissionModel
{
public string foo { get; set; }
public Submission submission { get; set; }
}
The simple model
[Table(Name = "Submission")]
public class Submission
{
[Column(IsPrimaryKey = true, IsDbGenerated = true, AutoSync = AutoSync.OnInsert)]
public int SubmissionId { get; set; }
[Column]
public string Title { get; set; }
}
The view:
#model Project.WebUI.Models.EditSubmissionModel
#{
ViewBag.Title = "editSubmission";
}
<h2>editSubmission</h2>
#using (Html.BeginForm())
{
<legend>SubmissionModel</legend>
#Html.EditorFor(m => m.foo)
#Html.EditorFor(m => m.submission)
<input type="submit" value="Save" />
}
the editorTemplate
#model Project.Domain.Entities.Submission
#Html.EditorFor(m => m.Title)
the controller
[Authorize]
[HttpPost]
public ActionResult editSubmission(string shortName, EditSubmissionModel model)
{
shortname = "second" (is ok)
model.foo = aaa (also ok i edited it on the view)
model.submission = null (not binded? or i dont know?)
I can't see the error, any ideas?

Status no repro. Steps:
Create a new ASP.NET MVC 3 application using the default template
Define 2 models:
public class Submission
{
public int SubmissionId { get; set; }
public string Title { get; set; }
}
public class EditSubmissionModel
{
public string foo { get; set; }
public Submission submission { get; set; }
}
Modify HomeController so that it looks like this:
public class HomeController : Controller
{
public ActionResult Index()
{
return View();
}
[HttpPost]
public ActionResult Index(string shortName, EditSubmissionModel model)
{
return Content(model.submission.Title);
}
}
Update ~/Views/Home/Index.cshtml view so that it looks like this:
#model EditSubmissionModel
#using (Html.BeginForm())
{
<legend>SubmissionModel</legend>
#Html.EditorFor(m => m.foo)
#Html.EditorFor(m => m.submission)
<input type="submit" value="Save" />
}
Add a custom editor template for the Submission type (~/Views/Home/EditorTemplates/.cshtml) like this:
#model Submission
#Html.EditorFor(m => m.Title)
Hit Ctrl+F5, fill in the form and submit. As totally expected the value you have entered in the Title textbox will be correctly bound and shown on the screen.
So I repeat the question that I've already asked you in the comments section: what did you do differently? You answered that it is a copy-paste from your code, but as I have illustrated you (with a full step-by-step guide) this is not the case.
Now here's a suspicion that I have. Your actual POST action looks like this:
public ActionResult editSubmission(string shortName, EditSubmissionModel submission)
and not like this:
public ActionResult editSubmission(string shortName, EditSubmissionModel model)
Notice the parameter name.

#Darin Dimitrov you were completely right, what do i do different. The code above was completely fine. The problem was the get command which looked like:
[Authorize]
public ActionResult editSubmission(string confShortName, string submission)
{
//do stuff
return View();
}
And the Modelbinder will get problems if the httpPost anywhere has same name like the HttpGet in my case string submission and Editsubmission.submission. Big thanks to your detailed step by step advice!

ASP.NET MVC - Modelbinding with Dropdownlist

Is it possible to have a single view model with a list that is used for a dropdownlist and also get the selected value of the dropdownlist from the view model when I post a form?
If so, how can I do this?

Sure, as always start by defining your view model:
public class MyViewModel
{
public int? SelectedItemValue { get; set; }
public IEnumerable<Item> Items { get; set; }
}
public class Item
{
public int? Value { get; set; }
public string Text { get; set; }
}
then the controller:
public class HomeController : Controller
{
public ActionResult Index()
{
var model = new MyViewModel
{
// TODO: Fill the view model with data from
// a repository
Items = Enumerable
.Range(1, 5)
.Select(i => new Item
{
Value = i,
Text = "item " + i
})
};
return View(model);
}
[HttpPost]
public ActionResult Index(MyViewModel model)
{
// TODO: based on the value of model.SelectedItemValue
// you could perform some action here
return RedirectToAction("Index");
}
}
and finally the strongly typed view:
<% using (Html.BeginForm()) { %>
<%= Html.DropDownListFor(
x => x.SelectedItemValue,
new SelectList(Model.Items, "Value", "Text")
) %>
<input type="submit" value="OK" />
<% } %>