ASP。NET MVC 2预览1 -带有复杂模型对象的DataAnnotation验证

The ability to let the model handle its own validation has lead me to begin playing with the MVC 2 preview release. So far, I like the simplicity of the validation scheme. However, I have run into a roadblock. This validation style works fine for simple view model objects. For example if I have a model object named car and I'm looking to create a view to create a new car:

让模型自己处理验证的能力使我开始使用MVC 2预览版。到目前为止，我喜欢验证方案的简单性。然而，我遇到了障碍。这种验证风格适用于简单的视图模型对象。例如，如果我有一个名为car的模型对象，我想创建一个视图来创建一个新汽车:

-----Model-------

- - - - -模型- - - - - - -

public class Car
{
    public string Id { get; set; }
    public string Name { get; set; }
    public string Color { get; set; }
}

-----Controller---------

- - - - - - - - - - - -控制器

public class CarController : Controller
{
    public ActionResult Create()
    {
        Car myCar = new Car();
        return View("Create", myCar);

    }

    [HttpPost]
    public ActionResult Create(Car myCar)
    {
        if (!ModelState.IsValid)
        {
            return View("Create", myCar);
        }

        //Do something on success
        return View("Index");

    }

}

-------View--------------

- - - - - -查看- - - - - - - - - - - - - - -

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

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

    <%= Html.ValidationSummary("Edit was unsuccessful. Please correct the errors and try again.") %>

    <% 
        using (Html.BeginForm()) {%>

        <fieldset>
            <legend>Edit User Profile</legend>
            <p>
                <label for="Id">Id:</label>
                <%= Html.TextBox("Id", Model.Id)%>
                <%= Html.ValidationMessage("Id") %>
            </p>
            <p>
                <label for="Name">Name:</label>
                <%= Html.TextBox("Name", Model.Name)%>
                <%= Html.ValidationMessage("Name") %>
            </p>
            <p>
                <label for="Color">Color:</label>
                <%= Html.TextBox("Color", Model.Color)%>
                <%= Html.ValidationMessage("Color") %>
            </p>

            <p>
                <input type="submit" value="Save" />
            </p>
        </fieldset>

    <% } %>

</asp:Content>

This works like a charm. But not all of my views, or model objects for that matter, are simple. I might have a car model object like:

这就像一种魅力。但并不是我的所有视图或模型对象都很简单。我可能有一个汽车模型对象，比如:

-----Model-------

- - - - -模型- - - - - - -

public class PaintScheme
{
    public int Red { get; set; }
    public int Blue { get; set; }
    public int Green { get; set; }
}

public class Car
{
    public string Id { get; set; }
    public string Name { get; set; }
    public PaintScheme Paint{ get; set; }
}

-------View--------------

- - - - - -查看- - - - - - - - - - - - - - -

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

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

    <%= Html.ValidationSummary("Edit was unsuccessful. Please correct the errors and try again.") %>

    <% 
        using (Html.BeginForm()) {%>

        <fieldset>
            <legend>Edit User Profile</legend>
            <p>
                <label for="Id">Id:</label>
                <%= Html.TextBox("Id", Model.Id)%>
                <%= Html.ValidationMessage("Id") %>
            </p>
            <p>
                <label for="Name">Name:</label>
                <%= Html.TextBox("Name", Model.Name)%>
                <%= Html.ValidationMessage("Name") %>
            </p>
            <p>
                <label for="Red">Color Red:</label>
                <%= Html.TextBox("Red", Model.Paint.Red)%>
                <%= Html.ValidationMessage("Red") %>
            </p>
            <p>
                <label for="Blue">Color Blue:</label>
                <%= Html.TextBox("Blue", Model.Paint.Blue)%>
                <%= Html.ValidationMessage("Blue") %>
            </p>
            <p>
                <label for="Green">Color Green:</label>
                <%= Html.TextBox("Green", Model.Paint.Green)%>
                <%= Html.ValidationMessage("Green") %>
            </p>

            <p>
                <input type="submit" value="Save" />
            </p>
        </fieldset>

    <% } %>

</asp:Content>

When I add the PaintScheme properties to my view, they are not carried over with the "myCar" object passed into my controller action. Is there a way to resolve this without having to rebuild the object from a form collection and then checking the ModelState?

当我将PaintScheme属性添加到视图中时，它们不会与传递到控制器动作中的“myCar”对象一起传递。是否有一种方法可以解决这个问题，而不必从表单集合中重新构建对象，然后检查ModelState?

3 个解决方案

#1

1. You should have the public setter for properties you want to be bound. I wonder how the first sample works for you as everything is private.
2. 您应该拥有要绑定的属性的公共setter。我想知道第一个示例是如何工作的，因为一切都是私有的。
3. You have to post at least one value of PaintScheme property to be able to bind it.
4. 您必须发布至少一个值的PaintScheme属性才能绑定它。
5. All child properties should be prefixed with the path to it. Where path can be defined as *(PropertyName.)**.
6. 所有子属性都应该以指向它的路径为前缀。其中路径可以定义为*(PropertyName.)**。

It seems the point 3 is not satisfied in the View. Change the appropriate part of the view to this:

看来第三点在观点上并不令人满意。将视图的适当部分改为:

        <p>
            <label for="Red">Color Red:</label>
            <%= Html.TextBox("Paint.Red")%>
            <%= Html.ValidationMessage("Red") %>
        </p>
        <p>
            <label for="Blue">Color Blue:</label>
            <%= Html.TextBox("Paint.Blue")%>
            <%= Html.ValidationMessage("Blue") %>
        </p>
        <p>
            <label for="Green">Color Green:</label>
            <%= Html.TextBox("Paint.Green")%>
            <%= Html.ValidationMessage("Green") %>
        </p>

Additionally note that I removed explicit values from the TextBox helper to avoid possible NullReferenceException.

另外请注意，我从文本框helper中删除了显式值，以避免可能的NullReferenceException。

#2

The easiest way to deal with this is to flatten your model using a dto. Then use automapper to map your domain object to your view model. This translation could be defined in such a way that you convert the enum to a string and back. Then validation will work and your bom won't touch the view maintaining your seperation of concerns fairly well.

处理此问题的最简单方法是使用dto使模型变平。然后使用automapper将域对象映射到视图模型。可以用这样的方式定义这个转换，将enum转换为字符串并返回。然后验证将起作用，而您的bom将不会触及保持您的关注点隔离的视图。

#3

For the color part you can have something like this, being an int I dont think you will use a textbox but this will bind your red color (if the input value is a number)

对于颜色部分，你可以有这样的东西，作为一个int类型我不认为你会使用一个文本框但是这会绑定你的红色(如果输入值是一个数字)

 <p>
                <label for="Red">Color:</label>
                <%= Html.TextBox("Red", Model.Paint.Red)%>
                <%= Html.ValidationMessage("Red") %>
 </p>