MVC的UpdateModel当名称不匹配 [英] MVC UpdateModel when the names don't match up

问题描述

让我们说你有一个模型，看起来有点像这样的：

Let's say that you have a Model that looks kind of like this:

public class MyClass {
    public string Name { get; set; }
    public DateTime MyDate { get; set; }
}

这是Visual Studio中为您提供了默认的编辑模板是数值指明MyDate 属性的纯文本框。这是一切优秀和良好的，但让我们说，你需要拆分成它的月/日/年的组件，并且您的形式如下：

The default edit template that Visual Studio gives you is a plain textbox for the MyDate property. This is all fine and good, but let's say that you need to split that up into it's Month/Day/Year components, and your form looks like:

<label for="MyDate">Date:</label>
<%= Html.TextBox("MyDate-Month", Model.MyDate.Month) %>
<%= Html.TextBox("MyDate-Day", Model.MyDate.Day) %>
<%= Html.TextBox("MyDate-Year", Model.MyDate.Year) %>

在此被提交，到的UpdateModel 通话将无法工作，因为没有为数值指明MyDate个月的定义。有没有办法将自定义粘结剂添加到项目中来处理这种情况，或者如果HTML输入名称不同（无论何种原因）？

When this is submitted, a call to UpdateModel won't work, since there isn't a definition for MyDate-Month. Is there a way to add a custom binder to the project to handle situations like this, or if the HTML inputs are named differently (for whatever reasons)?

一个解决办法，我发现是使用JavaScript注入一个隐藏的输入到该地连接了场，并正确命名之前提交的形式，但感觉错了。

One workaround I've found is to use JavaScript to inject a hidden input into the form before submission that concatenates the fields and is named properly, but that feels wrong.

推荐答案

我会建议你自定义的模型绑定：

I would suggest you a custom model binder:

using System;
using System.Globalization;
using System.Web.Mvc;

public class MyClassBinder : DefaultModelBinder
{
    protected override object CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType)
    {
        var model = (MyClass)base.CreateModel(controllerContext, bindingContext, modelType);

        var day = bindingContext.ValueProvider["MyDate-Day"];
        var month = bindingContext.ValueProvider["MyDate-Month"];
        var year = bindingContext.ValueProvider["MyDate-Year"];

        var dateStr = string.Format("{0}/{1}/{2}", month.AttemptedValue, day.AttemptedValue, year.AttemptedValue);
        DateTime date;
        if (DateTime.TryParseExact(dateStr, "MM/dd/yyyy", null, DateTimeStyles.None, out date))
        {
            model.MyDate = date;
        }
        else
        {
            bindingContext.ModelState.AddModelError("MyDate", "MyDate has invalid format");
        }

        bindingContext.ModelState.SetModelValue("MyDate-Day", day);
        bindingContext.ModelState.SetModelValue("MyDate-Month", month);
        bindingContext.ModelState.SetModelValue("MyDate-Year", year);

        return model;
    }
}

这简化了您的控制器动作：

This simplifies your controller action to:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult MyAction(MyClass myClass)
{
    if (!ModelState.IsValid)
    {
        return View(myClass);
    }
    // Do something with myClass
    return RedirectToAction("success");
}

和在Global.asax中注册粘结剂：

And register the binder in Global.asax:

protected void Application_Start()
{
    RegisterRoutes(RouteTable.Routes);
    ModelBinders.Binders.Add(typeof(MyClass), new MyClassBinder());
}

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