.net - MVC3 客户端对集合的验证，至少有一个元素具有值

Question

我的 View 模型

Public Class ViewModel
  <SelectOne()>
  Public Property Collection As List(Of Item)
End Class

我的模特

Public Class Item
  <SelectOneProperty(TargetValue:=True, ErrorMessage:="Select at least one.")>
  Public Property Selected As Boolean
  Public Property Value As String
End Class

在我看来，我正在渲染 ViewModel.Collection使用编辑器模板

@Html.CheckBoxFor(Function(item) item.Selected)
@Html.HiddenFor(Function(item) item.Value)

现在，我想要的是确保使用客户端验证至少选中一个复选框。

我可以通过在 Item.Selected 上设置自定义验证属性来实现这一点。属性并通过 $.validator.unobtrusive.adapters.add() 注册新适配器

但我觉得属性应该放在 ViewModel.Collection上在服务器端的属性我已经在验证集合的项目之一是否具有 Selected = True使用此自定义验证:

<AttributeUsage(AttributeTargets.Field Or AttributeTargets.Property, AllowMultiple:=False, Inherited:=False)>
Public Class SelectOneAttribute
    Inherits ValidationAttribute

    Protected Overrides Function IsValid(value As Object, validationContext As ValidationContext) As ValidationResult

        Dim list As IList

        If value Is Nothing Then
            Return Nothing
        End If

        If TypeOf value Is IEnumerable Then
            list = CType(value, IList)
        Else
            list = New Object() {value}
        End If

        Dim count As Integer = (From item In list
                                From prop In item.GetType().GetProperties()
                                Let attributes = prop.GetCustomAttributes(GetType(RequireOneOrMoreIndicatorAttribute), False)
                                Where attributes.Count > 0
                                From attribute In attributes
                                Where attribute.TargetValue = prop.GetValue(item, Nothing)).Count()
        If count > 0 Then
            Return Nothing
        End If

        Return New ValidationResult(FormatErrorMessage(validationContext.DisplayName))
    End Function
End Class

它在 SelectOnePropertyAttribute 上使用反射查找要检查的属性:

<AttributeUsage(AttributeTargets.Field Or AttributeTargets.Property, AllowMultiple:=False, Inherited:=False)>
Public Class SelectOnePropertyAttribute
    Inherits ValidationAttribute
    Implements IClientValidatable

    Public Property TargetValue As Object

    Public Sub New(targetValue As Object)
        Me.TargetValue = targetValue
    End Sub

    Public Overrides Function IsValid(value As Object) As Boolean
        Return True
    End Function

    Public Function GetClientValidationRules(metadata As System.Web.Mvc.ModelMetadata, context As System.Web.Mvc.ControllerContext) _
        As System.Collections.Generic.IEnumerable(Of System.Web.Mvc.ModelClientValidationRule) _
        Implements System.Web.Mvc.IClientValidatable.GetClientValidationRules

        Dim rule As New ModelClientValidationRule With {
            .ValidationType = "selectone",
            .ErrorMessage = Me.ErrorMessage
        }

        Return New ModelClientValidationRule() {rule}
    End Function
End Class

这是客户端验证

$.validator.unobtrusive.adapters.add("selectone", function (options) {
    options.rules["selectone"] = {};
    options.messages["selectone"] = options.message;
});

$.validator.addMethod("selectone", function (value, element, parameters) {

    var $el = $(element),
        name = $el.attr("name"),
        field = name.replace(/\[.*$/, "").replace(".", "_"),
        attr = name.replace(/^.*\./, ""),
        test = new RegExp(field + "\\[\\d\\]\." + attr);

    var inputs = $("input[id^=" + field + "]:not([disabled]):not([type=hidden])").filter("input[name$=" + attr + "]");

    for(var i = 0; i < this.errorList.length; i++) {
        var name = $(this.errorList[i].element).attr("name");

        // Do not write out the error more than once.
        if (test.test(name)) return true;
    }

    return inputs.length == 0 || inputs.filter(":checked:not([disabled])").val();
});

Answer 1

您正在创建将在侧面运行的自定义验证，但如果您想在客户端运行，那么您必须为该自定义验证创建 JQuery，然后将其添加到您的页面。

请引用以下链接

http://www.codeproject.com/Articles/275056/Custom-Client-Side-Validation-in-ASP-NET-MVC3

http://www.falconwebtech.com/post/2012/04/21/MVC3-Custom-Client-Side-Validation-with-Unobtrusive-Ajax.aspx