Validation 根据属性有条件地要求类中的所有字段

我有一个Address类，用于两个属性—MailingAddress和StreetAddress

我如何才能使StreetAddress成为必需而MailingAddress不是

    public Address MailingAddress { get; set; }

    [Required(ErrorMessage = "Address, city, state, and zip code are required.")]
    public Address StreetAddress { get; set; }


 public class Address
    {
        [DisplayName("Address")]
        public string StreetAddress { get; set; }
        [DisplayName("City")]
        public string City { get; set; }
        [DisplayName("State")]     
        public string SelectedState { get; set; }
        [DataType(DataType.PostalCode)]
        [RegularExpression(@"^\d{5}$|^\d{5}-\d{4}$", ErrorMessage="The postal code should be in the format 00000 or 00000-0000")]
        [DisplayName("Zip")]
        public string Zip { get; set; }
    }

---

我会以不同的方式对待他们。我建议我们有两个不同的地址模型，并将它们放在一个viewModel中

让我们以您的

地址

类为例，给它一些

虚拟

关键字，以便重写类属性

public class Address
{
    [DisplayName("Address")]
    public virtual string StreetAddress { get; set; }
    [DisplayName("City")]
    public virtual string City { get; set; }
    [DisplayName("State")]     
    public virtual string SelectedState { get; set; }
    [DataType(DataType.PostalCode)]
    [RegularExpression(@"^\d{5}$|^\d{5}-\d{4}$", ErrorMessage="The postal code should be in the format 00000 or 00000-0000")]
    [DisplayName("Zip")]
    public virtual string Zip { get; set; }
}

现在，让我们创建一个继承Address类的新模型

public class MandatoryAddress : Address
{
    [Required]
    public override string StreetAddress { get; set; }
    [Required]
    public override string City { get; set; }
    [Required]
    public override string SelectedState { get; set; }
    [Required]
    public override string Zip { get; set; }
}

现在，让我们创建我们的视图模型

public class MyFormViewModel
{
    public MandatoryAddress StreetAddress { get; set; }
    public Address MailingAddress { get; set; }
}

视图可能如下所示

@{
    ViewBag.Title = "My Sample Form";
}

@model TestApp.Models.MyFormViewModel

<h2>@ViewBag.Title</h2>

@using (Html.BeginForm())
{
    <fieldset>
        <legend>Street Address</legend>
        <div>
            @Html.LabelFor(x => x.StreetAddress.StreetAddress)
            @Html.EditorFor(x => x.StreetAddress.StreetAddress)
            @Html.ValidationMessageFor(x => x.StreetAddress.StreetAddress)
        </div>
        <div>
            @Html.LabelFor(x => x.StreetAddress.City)
            @Html.EditorFor(x => x.StreetAddress.City)
            @Html.ValidationMessageFor(x => x.StreetAddress.City)
        </div>
        <div>
            @Html.LabelFor(x => x.StreetAddress.SelectedState)
            @Html.EditorFor(x => x.StreetAddress.SelectedState)
            @Html.ValidationMessageFor(x => x.StreetAddress.SelectedState)
        </div>
        <div>
            @Html.LabelFor(x => x.StreetAddress.Zip)
            @Html.EditorFor(x => x.StreetAddress.Zip)
            @Html.ValidationMessageFor(x => x.StreetAddress.Zip)
        </div>
    </fieldset>
    <fieldset>
        <legend>Mailing Address</legend>
        <div>
            @Html.LabelFor(x => x.MailingAddress.StreetAddress)
            @Html.EditorFor(x => x.MailingAddress.StreetAddress)
            @Html.ValidationMessageFor(x => x.MailingAddress.StreetAddress)
        </div>
        <div>
            @Html.LabelFor(x => x.MailingAddress.City)
            @Html.EditorFor(x => x.MailingAddress.City)
            @Html.ValidationMessageFor(x => x.MailingAddress.City)
        </div>
        <div>
            @Html.LabelFor(x => x.MailingAddress.SelectedState)
            @Html.EditorFor(x => x.MailingAddress.SelectedState)
            @Html.ValidationMessageFor(x => x.MailingAddress.SelectedState)
        </div>
        <div>
            @Html.LabelFor(x => x.MailingAddress.Zip)
            @Html.EditorFor(x => x.MailingAddress.Zip)
            @Html.ValidationMessageFor(x => x.MailingAddress.Zip)
        </div>
    </fieldset>

    <div>
        <input type="submit" />
    </div>
}

额外体验积分：

---

另一种方法（更复杂，但可以说“更好”）是创建自己的自定义

[必需]

属性，您可以将该属性应用于类（即

StreetAddress

）。属性必须遍历类的每个属性并应用

[必需]

属性。

谢谢Rowan。关于“专家”解决方案，该属性是特定于my Address类的，还是可以用于任何类的通用[必需]属性？你能举个例子吗？在仔细研究之后，这个方法比我想象的还要复杂。很可能是如此复杂，以至于这实际上是一个不好的方向。模型通常是透明的（它们很容易向你展示自己的一切），而且它们非常小，这通常意味着它们可以重复一点。关键是要明确你的意图。记住这一点，请继续上面的代码示例。

public class FormController : Controller
{
    //
    // GET: /Form/

    [HttpGet]
    public ActionResult Index()
    {
        MyFormViewModel viewModel = new MyFormViewModel();
        return View(viewModel);
    }

    [HttpPost]
    public ActionResult Index(MyFormViewModel viewModel)
    {
        return View(viewModel);
    }

}