使用实体数据模型的自定义验证 MVC 3

Question

我正在开发一个使用 MVC3 的项目。我首先创建了一个数据库（具有 PK 和 FK 等必要的约束），并使用 ADO.NET 实体数据模型将此数据库添加到我的 Web 应用程序中。一切似乎都工作正常，但我无法使验证灵活。这里有一些代码来澄清我的问题。

---

编辑：添加了视图+正确的模型。这个版本没有导入数据库，但结果是一样的。

---

--Models----

namespace CustomValidation.Models
{
    public class Person : IValidatableObject
    {   

    public int Id { get; set; }
    [Required]
    public String FirstName { get; set; }
    [Required]
    public String LastName { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        if (String.IsNullOrEmpty(FirstName))
        {
            var field = new[] { "FirstName" };
            yield return new ValidationResult("Firstname can't be null", field);
        }
    }
}
}



namespace CustomValidation.Models
{
    public class Address : IValidatableObject
    {

    public int Id { get; set; }
    [Required]
    public String Streetname { get; set; }
    [Required]
    public String Zipcode { get; set; }
    [Required]
    public String City { get; set; }
    [Required]
    public String Country { get; set; }
    public Person Person { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        if (String.IsNullOrEmpty(Streetname))
        {
            var field = new[] { "Streetname" };
            yield return new ValidationResult("Streetname can't be null", field);
        }
    }
}
}


public class MasterModel
{
    public List<Address> Addressess { get; set; }
    public Person Person { get; set; }
    }
}





namespace CustomValidation.Models
{
    public class DBEntities : DbContext
    {
    public DbSet<Person> People { get; set; }
    public DbSet<Address> Addressess { get; set; }
    }
}

----Controller----

namespace CustomValidation.Controllers
{
public class HomeController : Controller
{
    public ActionResult Index()
    {
        MasterModel Model = new MasterModel();
        Model.Person = new Person();
        Model.Addressess = new List<Address>();
        Model.Addressess.Add(new Address());
        Model.Addressess.Add(new Address());
        return View(Model);
    }


    [HttpPost]
    public ActionResult Index(MasterModel Model)
    {
        DBEntities _db = new DBEntities();
        if (TryValidateModel(Model.Person))
        {
            _db.People.Add(Model.Person);
            _db.SaveChanges();
        }
        else
        {
            return View(Model);
        }

        for (int i = 0; i < Model.Addressess.Count; i++)
        {
            if (!String.IsNullOrEmpty(Model.Addressess[i].Country))
            {
                if (TryValidateModel(Model.Addressess[i]))
                {
                    Model.Addressess[i].Person = Model.Person;
                    _db.Addressess.Add(Model.Addressess[i]);
                    _db.SaveChanges();
                }
                else
                {
                    return View(Model);
                }
            }
        }
        return RedirectToAction("Index");
    }
 }

这是我的视图：

@model CustomValidation.Models.MasterModel
@{
ViewBag.Title = "Index";
}

<h2>Create</h2>

@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
<legend>Person</legend>
<div class="editor-label">
@Html.LabelFor(m => Model.Person.FirstName)
@Html.EditorFor(m => Model.Person.FirstName)
</div>
<div class="editor-label">
@Html.LabelFor(m => Model.Person.LastName)
@Html.EditorFor(m => Model.Person.LastName)
</div>

</fieldset>
for (int i = 0; i < Model.Addressess.Count; i++)
{
<fieldset>
    <legend>Address</legend>

    <div class="editor-label">
        @Html.LabelFor(model => Model.Addressess[i].Streetname)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.Addressess[i].Streetname)
        @Html.ValidationMessageFor(model => Model.Addressess[i].Streetname)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => Model.Addressess[i].Zipcode)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => Model.Addressess[i].Zipcode)
        @Html.ValidationMessageFor(model => Model.Addressess[i].Zipcode)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => Model.Addressess[i].City)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => Model.Addressess[i].City)
        @Html.ValidationMessageFor(model => Model.Addressess[i].City)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => Model.Addressess[i].Country)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => Model.Addressess[i].Country)
        @Html.ValidationMessageFor(model => Model.Addressess[i].Country)
    </div>

</fieldset>

}
    <p>
        <input type="submit" value="Create" />
    </p>
}

问题（我在调试类似的东西时注意到）是，在请求进入我的操作之前，MVC 首先运行验证器你的收藏。因此，如果我只在表单中填写了 Person，那么在验证 Model.Person 时，它只会返回 false（我猜是因为地址的必填字段），因此它将反弹回我的视图。

我需要一些解决方法，让我决定要在操作中验证集合的哪些实例。

经过大量时间在网上搜索后，我一直无法找到任何解决方案。

我希望有人能帮助我。

附言。我是 Visual Studio 和 MVC 3 的新手，所以请不要对我太苛刻:)

Answer 1

为了验证返回到您的操作的模型的子模型，您需要将 TryValidateModel 应用到特定的子模型，并使用包含模型前缀的重载。如果您查看生成的 HTML，您将看到“人员”字段以 Person 作为前缀，第一个地址字段以 Addressess[0] 作为前缀，并且第二个地址字段以 Addressess[1] 作为前缀。

另外，在调用TryValidateModel之前必须清除所有模型错误（否则现有错误将导致TryValidateModel返回false）。

执行以下操作：

[HttpPost]
public ActionResult Index(MasterModel model)
{
    var reloadView = true;

    // clear any existing errors
    foreach (var key in ModelState.Keys)
        ModelState[key].Errors.Clear();

    if (TryValidateModel(model.Person, "Person"))   
    {   
        _db.People.Add(model.Person);   
        _db.SaveChanges();   
        reloadView = false;

        for (var i = 0; i < model.Addressess.Count(); i++)
        {
            foreach (var key in ModelState.Keys)
                ModelState[key].Errors.Clear();

            if (TryValidateModel(model.Addressess[i], "Addressess[" + i.ToString() + "]"))
            {
                **// UPDATED CODE**
                // add Person to Address model
                model.Addressess[i].Person = model.Person;

                _db.Addressess.Add(model.Addressess[i]);   
                _db.SaveChanges();   
            }
        }
    }

    if (reloadView)
    {
        // clear and re-add all errors
        foreach (var key in ModelState.Keys)
            ModelState[key].Errors.Clear();

        TryValidateModel(model);
        return View(model);
    }
    else
    {
        // go to some other view
    }
}