Question

我已经阅读了很多关于null模型的类似帖子，但我的情况非常简单，而且仍然是Create action上的模型为null。我究竟做错了什么？？？

以下是这种情况：一个主视图，内部有两个强类型的局部视图，每个视图都绑定到主模型的公共属性。任何帮助表示赞赏。的模型：

public class SimpleModel1
{
    public IEnumerable<string> SomeStrings1 { get; set; }
}

public class SimpleModel2
{
    public IEnumerable<string> SomeStrings2 { get; set; }
}

public class ComplexModel
{
    public SimpleModel1 model1 { get; set; }
    public SimpleModel2 model2 { get; set; }
    public IEnumerable<string> SomeStringsComplex { get; set; }
}

他控制器：

public ActionResult Create()
    {
        ComplexModel complex = new ComplexModel();
        complex.model1 = new SimpleModel1();
        complex.model1.SomeStrings1 = new List<string> { "a1", "a2", "a3"};

        complex.model2 = new SimpleModel2();
        complex.model2.SomeStrings2 = new List<string> { "b1", "b2", "b3" };

        complex.SomeStringsComplex = new List<string> { "c1", "c2", "c3" };
        return View(complex);
    }

    [HttpPost]
    public ActionResult Create(ComplexModel model)
    {
        if (ModelState.IsValid)
        {
            var test = model.SomeStringsComplex;
        }
        return View();
    }

视图： 2个强烈的局部视图 - 每个模型

<%@ Control Language="C#"     
Inherits="System.Web.Mvc.ViewUserControl<MvcApp1.Models.SimpleModel2>" %>

<fieldset>
    <legend>Fields</legend>
    <% foreach (string item in Model.SomeStrings2)
            {%>
            <p>
            <label for="Title">Item Title:</label>
            <%= Html.TextBox(item,item)%>               
            </p>
            <%
            }
         %>
</fieldset>

1主要观点：

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master"
    Inherits="System.Web.Mvc.ViewPage<MvcApp1.Models.ComplexModel>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
 Create
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

<h2>Create</h2>
 <% using (Html.BeginForm()) {%>
 <fieldset>
<div> Own values
<% foreach (string item in Model.SomeStringsComplex)
            {%>
            <p>
            <label for="Title">Item Title:</label>
            <%= Html.TextBox(item,item) %>          
            </p>
            <%
            }
         %>
</div>
<div>Simple values 1
<%Html.RenderPartial("SimpleModelView1", this.ViewData.Model.model1, new ViewDataDictionary()); %>
</div>

<div>Simple values 2
<%Html.RenderPartial("SimpleModelView2", Model.model2, new ViewDataDictionary()); %>
</div>
<p>
            <input type="submit" value="Create" />
        </p>
</fieldset>
 <% } %>

Answer 1

~~我将采取疯狂的刺，并说当将ComplexModel发布回服务器时，模型验证失败~~

您的模型验证根本不必失败。您没有从if块内返回任何内容，因此您总是返回一个没有关联模型的视图：

if (ModelState.IsValid)
{
    var test = model.SomeStringsComplex;
}
return View(); // View is called with no Model data

根据您的代码判断，这将导致Create视图在没有Model的情况下实例化。这可以很简单地解决：

[HttpPost]
public ActionResult Create(ComplexModel model)
{
    if (ModelState.IsValid)
    {
        var test = model.SomeStringsComplex;
        // Do something to Create the object

        RedirectToAction("Index");
    }

    // Model State is invalid, return so the user can correct
    return View(model);
}

Answer 2

你不应该在那条线上向视图发送内容吗？

return View();

Answer 3

我认为问题在于如何指定文本字段 - 模型绑定器不知道如何将它们分配回它们来自的属性。

您可能希望阅读这篇Haacked文章，该文章介绍了如何对可枚举属性使用模型绑定：

http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx

Answer 4

最后我找到了解决方案。发布到Create方法的数据应该是s.th.像这样：

[HttpPost]
public ActionResult Create(ComplexModel mainModel, SimpleModel nestedModel, SimpleModel2 nested2Model)
{
    if (ModelState.IsValid)
    {
        var main = mainModel;
        var nested1 = nestedModel;
        var nested2 = nested2Model;
    }

    return View();
}

当模型绑定到部分视图时，嵌套参数不为null。如果通过主模型在主窗体中使用，则值在主模型的实例中。我还将IEnumerable<string>更改为IList<string>，然后使用

呈现字符串值

for (int i = 0; i < Model.Strings.Count; i++)
{ %>
    <%: Html.EditorFor(m => m.Strings[i])%>
<% }

全部谢谢

模型是空的？

4 个答案: