自定义视图模型与MVC 2强类型HTML辅助返回上创建空的对象？ [英] Custom ViewModel with MVC 2 Strongly Typed HTML Helpers return null object on Create?

问题描述

我有一个麻烦，而试图创建一个模型自定义视图的实体创建表单。下面是我对分类创建表单自定义视图模式。

I am having a trouble while trying to create an entity with a custom view modeled create form. Below is my custom view model for Category Creation form.

public class CategoryFormViewModel
{
    public CategoryFormViewModel(Category category, string actionTitle)
    {
        Category = category;
        ActionTitle = actionTitle;
    }

    public Category Category { get; private set; }
    public string ActionTitle { get; private set; }
}

这是我的用户控制，其中用户界面是

and this is my user control where the UI is

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

        <h2>
            <span><%= Html.Encode(Model.ActionTitle) %></span>
        </h2>
        <%=Html.ValidationSummary() %>
        <% using (Html.BeginForm()) {%>
        <p>
            <span class="bold block">Başlık:</span>
            <%=Html.TextBoxFor(model => Model.Category.Title, new { @class = "width80 txt-base" })%>
        </p>
        <p>
            <span class="bold block">Sıra Numarası:</span>
            <%=Html.TextBoxFor(model => Model.Category.OrderNo, new { @class = "width10 txt-base" })%>
        </p>        
        <p>
            <input type="submit" class="btn-admin cursorPointer" value="Save" />
        </p>
        <% } %>

当我点击保存按钮，它不因为我使用的自定义视图模型绑定我的类别和强类型HTML辅助方法一样，

When i click on save button, it doesnt bind the category for me because of i am using custom view model and strongly typed html helpers like that

<%=Html.TextBoxFor(model => Model.Category.OrderNo) %>

我的HTML源代码看起来像这样

My html source looks like this

<form action="/Admin/Categories/Create" method="post">
        <p>
            <span class="bold block">Başlık:</span>
            <input class="width80 txt-base" id="Category_Title" name="Category.Title" type="text" value="" />
        </p>
        <p>
            <span class="bold block">Sıra Numarası:</span>
            <input class="width10 txt-base" id="Category_OrderNo" name="Category.OrderNo" type="text" value="" />
        </p>        
        <p>
            <input type="submit" class="btn-admin cursorPointer" value="Kaydet" />
        </p>
        </form>

我怎样才能解决这个问题？

How can i fix this?

推荐答案

您查看模型需要不带参数的默认构造函数，你需要为每个属性的公共set方法。默认的模型绑定使用公共setter方法​​来填充对象。

Your View Model needs a default constructor without parameters and you need public set methods for each of the properties. The default model binder uses the public setters to populate the object.

默认的模型粘合剂有一些它遵循的规则。它选择哪些数据绑定到以下顺序：

The default model binder has some rules it follows. It chooses what data to bind to in the following order:

1. 从后表单参数


2. 将您的路由定义中的global.asax.cs定义的URL路由数据


3. 查询字符串参数

默认的模型绑定，然后使用一些策略来绑定模型/在动作方法的参数：

The default model binder then uses several strategies to bind to models/parameters in your action methods:

1. 完全名称匹配


2. 以prefix.name，其中preFIX是父类和名称是子类/属性相匹配


3. 无preFIX（只要没有冲突，你不必担心提供preFIX）名称

您可以覆盖从绑定属性的几个选项的行为。这些措施包括：

You can override the behavior with several options from the Bind attribute. These include:

• [装订（preFIX =一些preFIX）] - 强制地图由preFIX确定一个特定的父类


• [绑定（包括=VAL1，将val2）] - 名字的白名单绑定到


• [绑定（不包括=VAL1，将val2）] - 名从默认的行为排除

• [Bind(Prefix = "someprefix")] -- Forces a map to a specific parent class identified by the prefix.
• [Bind(Include = "val1, val2")] -- Whitelist of names to bind to
• [Bind(Exclude = "val1, val2")] -- Names to exclude from default behavior

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