Asp.Net MVC 4 ModelState.IsValid返回False

Question

我開發一個Asp.Net MVC 4應用程序，我有這兩個示範類：

CompanyModel：

Public Class CompanyModel 

    <Key()> 
    Public Overridable Property CompanyID As Integer 

    <Required(ErrorMessage:="Enter a company name.")> 
    <Display(Name:="Company")> 
    <StringLength(80, ErrorMessage:="The {0} must have {2} characters.", MinimumLength:=2)> 
    Public Overridable Property Name As String 

    <Required(AllowEmptyStrings:=False, ErrorMessage:="Enter the DB ID.")> 
    <Display(Name:="DB ID")> 
    Public Overridable Property DBID As Integer 

End Class 

PersonModel：

Public Class PersonModel 

    <Key()> 
    Public Overridable Property PersonID As Integer 

    <Required(AllowEmptyStrings:=False, ErrorMessage:="Enter the name.")> 
    <Display(Name:="Name")> 
    Public Overridable Property Name As String 

    <Required(AllowEmptyStrings:=False, ErrorMessage:="Enter the pass")> 
    <DataType(DataType.Password)> 
    <Display(Name:="Password")> 
    Public Overridable Property Password As String 

    <Required(AllowEmptyStrings:=False, ErrorMessage:="Enter the mail")> 
    <Display(Name:="E-mail")> 
    Public Overridable Property Email As String 

    <Required(ErrorMessage:="Enter the company")> 
    <Display(Name:="Company")> 
    Public Overridable Property BcoID As CompanyModel 

End Class 

PersonController：

' 
' POST: /Person/Create 

<HttpPost()> _ 
Function Create(ByVal model As PersonModel) As ActionResult 
    Try 
     If ModelState.IsValid Then 
      personDAO.Save(model) 
     End If 

     Return RedirectToAction("Index") 
    Catch 
     Return View() 
    End Try 
End Function 

我在查看/人驗證碼/創建：

<div class="editor-label"> 
    @Html.LabelFor(Function(model) model.BcoID) 
</div> 
<div class="editor-field"> 
    @Html.DropDownListFor(Function(model) model.BcoID.CompanyID, New SelectList(ViewBag.Company, "CompanyID", "Name")) 
    @Html.ValidationMessageFor(Function(model) model.BcoID) 
</div> 

當我創造新的人，在PersonController當我嘗試保存我得到ModelState.Isvalid =假消息是「輸入一個公司名稱「。我不知道爲什麼會發生。

有人可以幫助我嗎？

編輯

如果我改變我從model.BcoID.CompanyID到model.BcoID.Name財產，我使用EditorFor，而不是使用DropDownListFor。 ModelState.IsValid是True，但我需要一個DropDownList，所以我放了一個DropDownList，現在我有一個驗證按摩（「公司必須有2個字符。」）在我的視圖。

這是我現在有：

<div class="editor-label"> 
    @Html.LabelFor(Function(model) model.BcoID.Name) 
</div> 
<div class="editor-field"> 
    @Html.DropDownListFor(Function(model) model.BcoID.Name, New SelectList(ViewBag.Company, "CompanyID", "Name")) 
    @Html.ValidationMessageFor(Function(model) model.BcoID.Name) 
</div> 

Answer 1

確保，因爲這個屬性是你的模型需要你有你的觀點公司名稱屬性：

<div class="editor-label"> 
    @Html.LabelFor(Function(model) model.BcoID.Name) 
</div> 
<div class="editor-field"> 
    @Html.EditorFor(Function(model) model.BcoID.Name) 
    @Html.ValidationMessageFor(Function(model) model.BcoID.Name) 
</div> 

而且標籤和ValidationMessage傭工被附加到您的CompanyID屬性的錯誤屬性。它應該是這樣的：

<div class="editor-label"> 
    @Html.LabelFor(Function(model) model.BcoID.CompanyID) 
</div> 
<div class="editor-field"> 
    @Html.DropDownListFor(Function(model) model.BcoID.CompanyID, New SelectList(ViewBag.Company, "CompanyID", "Name")) 
    @Html.ValidationMessageFor(Function(model) model.BcoID.CompanyID) 
</div> 

請注意Label和ValidationMessage現在是如何正確關聯到DropDownList的。