.net LINQ-如何根据DB将返回的值修改select

我对Linq比较陌生，我正在使用.NET开发一个函数，该函数用Linq查询的选定字段实例化一个实例

问题是其中一个字段必须“在运行时”转换

这是我的故障示例：

Private Shared Function GetInfectionHistory(HiveId As Long) As IList(Of HiveInfectionDetail)
    Using DB As LandDataModelUnitOfWork = Context.CreateUnitOfWork
            Dim historyResult = From I In DB.HiveAfbInfections
                                Where I.HiveId = HiveId
                                Select New HiveInfectionDetail With {
                                    .DateInfected = I.DateInfected,
                                    .DateCleaned = I.DateCleared,
                                    .PotentialAfbInfection = I.PotentialInfection,
                                    .AfbInfection = Not I.PotentialInfection
                                }
            If IsListEmpty(historyResult.ToList()) Then
                Return Nothing
            End If
            Return historyResult.ToList()
        End Using
End Function

及

有问题的一行是当我给属性afbinefection赋值时。此属性将与数据库中的PotentialInfection值相反。所以如果I.PotentialInfection为真，那么我的属性afbininfection应该为假。如上所述操作将导致IndexOutOfRangeException-Index超出了数组的边界不确定LinQ对该not表达式做了什么，但肯定不是我所希望的

在将DB字段值存储到我的自定义对象中时，有没有办法修改它

谢谢大家!

试试这个：

Private Shared Function GetInfectionHistory(HiveId As Long) As IList(Of HiveInfectionDetail)
    Using DB As LandDataModelUnitOfWork = Context.CreateUnitOfWork
            Dim historyQuery1 = From I In DB.HiveAfbInfections
                                Where I.HiveId = HiveId
                                Select New With {
                                    .DateInfected = I.DateInfected,
                                    .DateCleaned = I.DateCleared,
                                    .PotentialInfection = I.PotentialInfection
                                }
            Dim historyQuery2 = From I In historyQuery1.ToArray()
                                Select New HiveInfectionDetail With {
                                    .DateInfected = I.DateInfected,
                                    .DateCleaned = I.DateCleaned,
                                    .PotentialAfbInfection = I.PotentialInfection,
                                    .AfbInfection = Not I.PotentialInfection
                                }
            Dim historyResult = historyQuery2.ToList()
            If IsListEmpty(historyResult) Then
                Return Nothing
            End If
            Return historyResult
        End Using
End Function

---

我还尝试了.afbinefection=（I.PotentialInfection=False），但没有成功。当检查是否有结果时，它抛出相同的IndexOutOfRangeException。谢谢。您的解决方案工作得很好，但我想知道是否有可能在运行时使用修改所选字段的指令构建LINQ。

Private Shared Function GetInfectionHistory(HiveId As Long) As IList(Of HiveInfectionDetail)
    Using DB As LandDataModelUnitOfWork = Context.CreateUnitOfWork
            Dim historyQuery1 = From I In DB.HiveAfbInfections
                                Where I.HiveId = HiveId
                                Select New With {
                                    .DateInfected = I.DateInfected,
                                    .DateCleaned = I.DateCleared,
                                    .PotentialInfection = I.PotentialInfection
                                }
            Dim historyQuery2 = From I In historyQuery1.ToArray()
                                Select New HiveInfectionDetail With {
                                    .DateInfected = I.DateInfected,
                                    .DateCleaned = I.DateCleaned,
                                    .PotentialAfbInfection = I.PotentialInfection,
                                    .AfbInfection = Not I.PotentialInfection
                                }
            Dim historyResult = historyQuery2.ToList()
            If IsListEmpty(historyResult) Then
                Return Nothing
            End If
            Return historyResult
        End Using
End Function