用于编辑多个项目的mvc绑定ValidationMessageFor显示所有记录

Question

似乎我的问题类似于MVC model binding to edit a list not working但是我遇到的问题是返回的列表是Nothing。还试图遵循http://www.c-sharpcorner.com/uploadfile/4b0136/editing-multiple-records-using-model-binding-in-mvc/但转换为VB.NET

Function EditAll() As ActionResult
    Return View(db.Recipients.Where(Function(r) r.Type = "EMAIL").ToList())
End Function

<HttpPost()>
Public Function EditAll(recipients As List(Of Recipient)) As ActionResult
    'recipients is Nothing why???
    For Each item As Recipient In recipients
        Dim Existing_Recip As Recipient = db.Recipients.Find(item.ID)

        Existing_Recip.EmailAddress = item.EmailAddress
        Existing_Recip.Active = item.Active

    Next

    db.SaveChanges()

    Return View(recipients)

End Function

观点：

@ModelType List(Of ConcurBridge.Models.Concur.Recipient)
@Code
    ViewData("Title") = "EditAll"
    Layout = "~/Views/Shared/_Layout.vbhtml"
End Code

<h2>Edit All Recipients</h2>

@Using (Html.BeginForm("EditAll", "Recipients", FormMethod.Post))
    @<table class="table">
    @For i As Integer = 0 To Model.Count - 1
        @<tr>
            <td>
                @Html.Hidden("recipient.Index", i)
                @Html.TextBox("recipient[" + i.ToString + "].ID",
                    Model(i).ID, New With {.readonly = "readonly"})
            </td>
            <td>
                @Html.TextBox("recipient[" + i.ToString + "].EmailAddress",
                    Model(i).EmailAddress)
            </td>
            <td>
                @Html.CheckBox("recipient[" + i.ToString + "].Active",
                    Model(i).Active)
            </td>
        </tr>
    Next
        <tr>
            <td colspan="3">
                <input type="submit" value="Submit" />
            </td>
        </tr>
    </table>
End Using

型号：

<Table("MultiUseTable")>
Public Class Recipient
    Public Property ID As Integer
    Public Property Type As String
    <DataType(DataType.EmailAddress),
    Column("Value"),
    DisplayName("Email Address"),
    Required(AllowEmptyStrings:=False, ErrorMessage:="Email address is required")>
    Public Property EmailAddress As String
    Public Property Active As Boolean
End Class