Question

我有一个继承数据库模型的ViewModel。我无法弄清楚如何从数据库中填充ViewModel。

“视图模型”

Public Class CustomerView
    Inherits Customer

    Private lookUp As New LookUpData

    ReadOnly Property OwnerList As List(Of SelectListItem)
        Get
            Return lookUp.OwnersList(True)
        End Get
    End Property

End Class

“控制器”

Function Edit(Optional Id As Integer = Nothing) As ActionResult

    Dim model As New CustomerView

    model = (From c In db.Customers Where c.Id = Id AndAlso c.OrganisationId = s.OrganisationId).FirstOrDefault

    If model Is Nothing Then
        Return RedirectToAction("List")
    Else
        Return View(model)
    End If

End Function

我收到了无效的强制转换异常。

非常感谢任何帮助。

Answer 1

您的Linq查询返回（我假设）作为您需要投影到视图模型对象中的Customer对象的列表。通过添加select：

来更改您的Linq

model = (From c In db.Customers _
         Where c.Id = Id AndAlso _
         c.OrganisationId = s.OrganisationId _
         Select New CustomerView With { _
             .CompanyName = c.CompanyName, _
             .Address = c.Address, _
             .City = cust.City, _
             .Country = cust.Country}).FirstOrDefault

自从我做VB之后已经有一段时间了，但这应该可以工作或只需要调整。

从数据库模型填充ViewModel

1 个答案: