为什么asp.net模型绑定器无法将字符串值映射到具有相同名称的Object属性

Question

I have a model class named Server and I have created a new ServerToEdit viewModel class, as follow:-

public class ServerToEdit
    {
        public Server Server { get; set; }
       [Required]
        public String IPAddress { get; set; }
    }

Part of the Create view is:-

    model TMS.ViewModels.ServerToEdit

    @* This partial view defines form fields that will appear when creating and editing entities *@
     @Html.AntiForgeryToken()
    <div class="editor-label">
        @Html.LabelFor(model => model.Server.CustomerName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model =>model.Server.CustomerName)
        @Html.ValidationMessageFor(model =>model.Server.CustomerName)
    </div>
    <div class="editor-label">
       IP Address
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.IPAddress)
        @Html.ValidationMessageFor(model => model.IPAddress)
    </div>

IPAddress
<div class="editor-label">
    @Html.LabelFor(model =>model.Server.ILOIP)
</div>
<div class="editor-field">
    @Html.EditorFor(model =>model.Server.ILOIP)
    @Html.ValidationMessageFor(model =>model.Server.ILOIP)
</div>

The Create actin method is :-

[HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create(Server server, TechnologyIP technologyIP)
        {
           try 
           { 
               if (ModelState.IsValid) 
           {
                repository.InsertOrUpdateServer(server,technologyIP);
                repository.Save();
                return RedirectToAction("Index");
            }

but the model binder was not able to bind the IPAddress field inside my view to the TechnologyIP.IPAddress property? the technologyIP model class is :-

public class TechnologyIP
    {
        public String IPAddress { get; set; }

        public int ID { get; set; }
    }

Answer 1

On first look, I would imagine that it's because the model you passed to the view is not the same model you are asking for back. Change this line:

public ActionResult Create(Server server, TechnologyIP technologyIP)

to

public ActionResult Create(ServerToEdit serverToEdit)

and this line:

repository.InsertOrUpdateServer(server,technologyIP);

to

repository.InsertOrUpdateServer(serverToEdit.Server, serverToEdit.technologyIP);

Let us know how you get on.