Question

所以我正在使用实体框架，我之前用ado.net编写了一个函数来获取两个值，然后返回一个数据表，我做了一些操作。代码在下面

Protected Sub ddlFieldMappingProfile_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddlFieldMappingProfile.SelectedIndexChanged
        If ddlFieldMappingProfile.SelectedValue >= 0 Then
            btnImportData.Enabled = True
        End If
        If ddlFieldMappingProfile.SelectedValue <= 0 Then Return

        Dim lstHeaders As List(Of String)
        Dim dtMapping As New DataTable()

        Dim intCount As Integer = 0
        Try

            Using com As New Common
                With com
                     dtMapping = .getProfileFields(Convert.ToInt32(ddlFieldMappingProfile.SelectedValue))
                    IEMapping = .getProfileFields(Convert.ToInt32(ddlFieldMappingProfile.SelectedValue))
                    lstHeaders = .FileHeaders(FileUpl.FiletoRead, FileUpl.Delimiter)
                End With
            End Using

            dtMapping.Columns.Add("MatchIndex")

            For Each row As DataRow In dtMapping.Rows
                For intCount = 0 To lstHeaders.Count() - 1
                    If lstHeaders(intCount) = row.Item("Dump_FieldName") Then
                        row.Item("MatchIndex") = intCount
                        Exit For
                    Else
                        row.Item("MatchIndex") = -1
                    End If
                Next
            Next
            gdvFieldData.DataSource = dtMapping
            gdvFieldData.DataBind()
            gdvFieldData.Visible = True

        Catch ex As Exception
            Throw ex
        Finally
            dtMapping.Dispose()
            lstHeaders = Nothing
        End Try
    End Sub
But now that I am using entity frame work I have written the LINQ query like 

Dim Context As New ICOM_Model.IcomsEntities()
        Dim query = From F In Context.Incentive_Prepaid_FieldMapping Where F.Profile_ID = Profile_ID
                    Select New With {.Activations_FieldName = F.Activations_FieldName, .Dump_FieldName = F.Dump_FieldName}

匿名类型。请帮助我什么是返回类型以及我将如何在代码中操作ddlFieldMappingProfile_SelectedIndexChanged

Answer 1

在您的代码中，返回类型将是匿名的，具有两个属性“Activations_FieldName和Dump_FieldName”，您可以通过“query”对象访问该值。

您可以创建一个具有您按实体选择的属性的类，并填充该类对象。

class ABC{
string Activations_FieldName{get;set;}
string Dump_FieldName{get;set;}
}

Dim Context As New ICOM_Model.IcomsEntities()
        List<ABC> query = From F In Context.Incentive_Prepaid_FieldMapping Where F.Profile_ID = Profile_ID
                    Select New ABC With {.Activations_FieldName = F.Activations_FieldName, .Dump_FieldName = F.Dump_FieldName}

现在您可以在代码中使用此类对象。希望这有帮助。

匿名类型返回和操作的实体框架问题

1 个答案: