ASP.NET MVC-模型未在部分视图中绑定到Ajax.BeginForm

Question

I have a partial View AddOptionPartial which uses a model OptionViewModel . This partial view is loaded when its parent, Build is loaded. This Build view uses the model BuildViewModel .

The partial is loaded in using using @{Html.RenderPartial("AddOptionPartial", new OptionViewModel());} .

The partial looks like this:

@model SurveyService.ViewModels.OptionViewModel

@{
    Layout = null;
}
@using (Ajax.BeginForm("AddOption", "Manage", new AjaxOptions { OnSuccess = "handleSavedOptionChoice(data)", HttpMethod = "Post" }))
{ 
    <div class="form-group">
        @Html.LabelFor(m => m.ChoiceText)
        @Html.TextBoxFor(m => m.ChoiceValue, new { @class = "form-control" })
    </div>
    @Html.LabelFor(m => m.ChoiceValue)
    <div class="form-group">
        <div class="btn-group" data-toggle="buttons">
            <label class="btn btn-primary">
                @Html.RadioButtonFor(m => m.ChoiceValue, 1) True
            </label>
            <label class="btn btn-primary">
            @Html.RadioButtonFor(m => m.ChoiceValue, 0) False
            </label>
            <label class="btn btn-primary active">
                @Html.RadioButtonFor(m => m.ChoiceValue, 2, true) Text
            </label>
        </div>
    </div>
    <button type="submit">Create</button>
}

As you can see, i am trying to post this form using an Ajax call. The call refers to this function:

public ActionResult AddOption(OptionViewModel model)
{
    ***content of function***
}

However, when debugging, the model is an OptionViewModel object containing no data. I can not find a reason for this on SO, can someone please advise?

Answer 1

Try this:

       @using (Ajax.BeginForm("AddOption", "Manage",null, new AjaxOptions { OnSuccess = "handleSavedOptionChoice(data)", HttpMethod = "Post" }))



            public ActionResult AddOptionChoice([System.Web.Http.FromBody]OptionViewModel model)
            {
                ***content of function***
            }

Answer 2

@{Html.RenderPartial("AddOptionChoicePartial", new OptionViewModel());} passes exactly that; a new, presumably empty, OptionViewModel .

You should either pass in a pre-populated model (from the parent BuildViewModel ) like @{Html.RenderPartial("AddOptionChoicePartial", parentViewModel.SomeModel);} or construct the View Model from scratch in AddOptionChoice .

(Note also that you're calling "AddOptionChoicePartial" from Html.RenderPartial , but the Controller Action is named AddOptionChoice . They should match)

Also, in trying to recreate the model from your comments, you're using ChoiceText and ChoiceValue, which do not match OptionText and OptionValue.

Answer 3

Error in the code found:

@Html.LabelFor(m => m.ChoiceText)
@Html.TextBoxFor(m => m.ChoiceValue, new { @class = "form-control" })

@Html.RadioButtonFor(m => m.ChoiceValue, 1) True

Setting multiple values on a single parameter causes that parameter to act like a list, which only creates a ModelState error and will never fill the model.

To anyone who encounters a similar problem in the future: Debug your controller function and have a look at the ModelState in the debugger.

Thanks to everyone who advised.