asp.net-mvc - 如何将 "required"属性添加到 mvc razor View 模型文本输入编辑器

Question

我有以下 MVC 5 Razor HTML 助手:

@Html.TextBoxFor(m => m.ShortName, 
  new { @class = "form-control", @placeholder = "short name"})

我需要这个字段是必需的(即当用户在没有放置 value inn 的情况下导航时有一个红色轮廓)。在 WebForms HTML 5 中，我只能说 <input type="text" required />达到这个效果。
在 Razor 语法中完成此操作的正确语法是什么？

Answer 1

您可以使用 required html 属性，如果你想要:

@Html.TextBoxFor(m => m.ShortName, 
new { @class = "form-control", placeholder = "short name", required="required"})

或者您可以使用 RequiredAttribute .Net 中的类。使用 jQuery RequiredAttribute可以在前端和服务器端进行验证。如果你想走 MVC 路线，我建议阅读 Data annotations MVC3 Required attribute .

或者

你可以变得非常先进:

@{
  // if you aren't using UnobtrusiveValidation, don't pass anything to this constructor
  var attributes = new Dictionary<string, object>(
    Html.GetUnobtrusiveValidationAttributes(ViewData.TemplateInfo.HtmlFieldPrefix));

 attributes.Add("class", "form-control");
 attributes.Add("placeholder", "short name");

  if (ViewData.ModelMetadata.ContainerType
      .GetProperty(ViewData.ModelMetadata.PropertyName)
      .GetCustomAttributes(typeof(RequiredAttribute), true)
      .Select(a => a as RequiredAttribute)
      .Any(a => a != null))
  {
   attributes.Add("required", "required");
  }

  @Html.TextBoxFor(m => m.ShortName, attributes)

}

或者如果您需要它用于多个编辑器模板:

public static class ViewPageExtensions
{
  public static IDictionary<string, object> GetAttributes(this WebViewPage instance)
  {
    // if you aren't using UnobtrusiveValidation, don't pass anything to this constructor
    var attributes = new Dictionary<string, object>(
      instance.Html.GetUnobtrusiveValidationAttributes(
         instance.ViewData.TemplateInfo.HtmlFieldPrefix));

    if (ViewData.ModelMetadata.ContainerType
      .GetProperty(ViewData.ModelMetadata.PropertyName)
      .GetCustomAttributes(typeof(RequiredAttribute), true)
      .Select(a => a as RequiredAttribute)
      .Any(a => a != null))
    {
      attributes.Add("required", "required");
    }
  }
}

然后在您的模板中:

@{
  // if you aren't using UnobtrusiveValidation, don't pass anything to this constructor
  var attributes = this.GetAttributes();

  attributes.Add("class", "form-control");
  attributes.Add("placeholder", "short name");

  @Html.TextBoxFor(m => m.ShortName, attributes)

}

更新 1(适用于不熟悉 ViewData 的 Tomas)。

What's the difference between ViewData and ViewBag?

摘抄:

So basically it (ViewBag) replaces magic strings:

ViewData["Foo"]

with magic properties:

ViewBag.Foo