Asp.net MVC2-表单后绑定

Question

I can't for the life of me figure out what I'm doing wrong.

I have a SearchModel class that my view inherits from

 public class SearchModel
    {
        public String Something { get; set; }
        public List<SearchField> SearchFields { get; set; }
    }

public class SearchField
{
    [XmlIgnore]
    public Boolean Include { get; set; }

    [XmlAttribute("Required")]
    public Boolean Required { get; set; }

    [XmlAttribute("Field")]
    public String FieldName { get; set; }

    [XmlText]
    public String DisplayName { get; set; }

    [XmlIgnore]
    public FilterMethod FilterOperator { get; set; }

    [XmlIgnore]
    public String Value { get; set; }
}

I have a controller called SearchController

 public ActionResult Index()
        {
            SearchModel model = new SearchModel
                                    {
                                        Something = "Hello",
                                        SearchFields = customer.Config.Fields
                                    };

            return View(model);
        }

        [AcceptVerbs(HttpVerbs.Post)]
        public ActionResult Index(SearchModel searchModel)
        {            
            return View("Index", searchModel);
        }

The SearchController index page has this to render the fields

<% using (Html.BeginForm())
   {%>
<%= Html.TextBox("Something", Model.Something) %>
<% for (int i = 0; i < Model.SearchFields.Count; i++)
   {

%>              
<%= Html.Label(Model.SearchFields[i].DisplayName) %>
<%= Html.DropDownListFor(x => x.SearchFields[i].FilterOperator, Model.SearchFields[i].FilterOperator.ToSelectList(), new { @class = "textField" })%>
<%= Html.TextBoxFor(x => x.SearchFields[i].Value) %>

<%= Html.ValidationMessageFor(x => x.SearchFields[i].Value) %>

<% } %>
<button type="submit" value="Search" class="SearchBtn">
    Search</button>
<% } %>

When I modify the value of the SearchField .Value property and press the submit button, it posts to the public ActionResult Index(SearchModel searchModel) method.

The searchModel variable contains the collection SearchFields , however only the " Value " and " FilterOperator " properties are not null.

How can I include the other properties in the post, even if I don't want to explicitly list them in the form?

This image below shows the values being sent to the "index" display page

This image below shows the output from POST

Answer 1

If you want to have those values postbacked you need to either provide them in the view by having the fields as Hidden fields

Html.HiddenFor(m => m.searchFields[i].FilterOperator)

Or have some sort of factory that fills your Model with default values

Answer 2

Have a look at these posts. It may be useful to you
http://blog.stevensanderson.com/2010/01/28/editing-a-variable-length-list-aspnet-mvc-2-style/
http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx

Answer 3

How can I include the other properties in the post, even if I don't want to explicitly list them in the form?

You'll have to fetch them again or stuff them in a hiddenfield and basically let the user define your readonly data.

This is why I like to keep the PostModel as a property of the ViewModel. Then my post action method only needs the PostModel parameter. Otherwise, like in your example, you get back this hybrid ViewModel/PostModel and you need to figure out which properties to use.