MVC HttpPost强类型模型null

Question

View Model looks like this:

public class AsmenysInfoViewModel2
{
    public asmenys_info Asmenys_info { get; set; }
    public List<miestai> Miestai { get; set; }
    public string Test { get; set; }
}

And there are two actions. Get and Post.

    public ActionResult Index(long? id)
    {

        var model = new AsmenysInfoViewModel2();
        model.Test = "Test";
        model.Asmenys_info = BllFactory.DalFactory.AsmenysInfoDal.GetById(id.Value);
        return View(model);
    }
    [HttpPost]
    public ActionResult Index(AsmenysInfoViewModel2 asmenys_info)
    {
        var model = asmenys_info;
        return View(model);
    }

And my view looks like this:

@model MODELS.AsmenysInfoViewModel2
@{
    ViewBag.Title = "Index";
}
@using (Html.BeginForm("Index", "AsmenysInfo", FormMethod.Post))
{
    @Html.ValidationSummary()
    @Html.TextBoxFor(m => m.Asmenys_info.adresas)       

    <input type="submit" value="Išsaugoti" />
}

Doesn't matter if I use EditorFor or TextBoxFor - result is same. My model property "Asmenys_info" on posting is always null. If my class AsmenysInfoViewModel2 would not contain asmenys_info type property and would contain only "string, int etc" (no strongly typed) - it would work. My question is :

How to post View Model which has strongly typed property which on posting would not be null?

Answer 1

Your model has a property named Asmenys_info and the parameter in your POST method is also named asmenys_info . Internally the DefaultModelBinder reads the values of the form data which includes a value for Asmenys_info and attempts to set property Asmenys_info to that value but it fails because there is no conversion from a string to a complex object.

Change the name of the parameter to anything other than a name of a property in your model and it will bind fine, for example

[HttpPost]
public ActionResult Index(AsmenysInfoViewModel2 model)

Answer 2

Change the below line with another object name

 public ActionResult Index(AsmenysInfoViewModel2 asmenys_info)

in above method use any other name of object instead of asmenys_info .

because while mvc framework map your model with object there is confution in asmenys_info and Asmenys_info property of AsmenysInfoViewModel2 class.