ASP.NET MVC Persisting mdoel's ID value when Editing - asp.net-mvc

Question

public Edit(int? id){ /* Codes */ }
[HttpPost]
public Edit(Item model){ /* Codes */ }
I retrieve a copy of Item in the first Edit method, which would contain a value for ItemID. But when it gets to the HttpPost method, the id value's lost.
If switched to
public Edit(int? ItemID){ /* Codes */ }
[HttpPost]
public Edit(Item model){ /* Codes */ }
this way ItemID can be persisted in the Item model.
But is this a good way to handle it? Will ASP.NET MVC always be able to know that it needs to plug "ItemID" into Item?
and are there other ways to persist the ID value? Thanks.

Answer 1

I cannot understand how do you lose id at the HttpPost handling. Maybe you should check your binder and possibly write one for yourself? In my experience default binders are a little cumbersome. You could start from here although I don't pretend it's the best solution. In case you need to write many binders by hand take a look at some tools that could help you make conversion in declarative way like AutoMapper .

Answer 2

Have you tried adding the id as a parameter to the Post action?
public Edit(int? id){ /* Codes */ }
[HttpPost]
public Edit(int id, Item model){ /* Codes */ }
This way, when the form is posted back, the id will be populated from the URL.

Answer 3

Is the property on your Item model called ItemID? If so, then the default model binder won't populate it if you're passing around a field called ID. If you change your method signatures so that the parameter names match up with your Item property names it should work as expected.

Answer 4

Phil Haack had a post that may or may not be related to what you're doing.
Also, if you're not sending the ID out to the client as part of a form (hidden field or whatnot) and it isn't part of the POST URL then it would only make sense that you wouldn't have the ID field populated properly on POST.

Answer 5

The MVC 2 way of solving the ID issue is Optional URL Parameters.
If you're still on MVC 1 then use a binding attribute on the method argument:
[HttpPost]
public ActionResult Edit([Bind(Exclude = "ItemID")] Item model)
{
// ...
}

Answer 6

Little late answer but when using razor its common to use a hidden field in order to bind the Id to the model.
#Html.HiddenFor(model => model.Id)
A complete form post could look like this:
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Address</h4>
<hr />
#Html.ValidationSummary(true, "", new { #class = "text-danger" })
#Html.HiddenFor(model => model.Id)
<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>
<div class="form-group">
#Html.LabelFor(model => model.StreetLine1, htmlAttributes: new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.EditorFor(model => model.StreetLine1, new { htmlAttributes = new { #class = "form-control" } })
#Html.ValidationMessageFor(model => model.StreetLine1, "", new { #class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Save" class="btn btn-default" />
</div>
</div>
</div>
}