vb.net - Linq多个字段组-VB.NET，匿名， key

Question

我很沮丧我需要帮助。我有一个重复的患者地址数据的DTO对象。我只需要获得唯一的地址。

Dim PatientAddressDto = New List(Of PatientAddress)

{Populate PatientAddressDto with lots of duplicate data}

PatientAddressDto = (From d In PatientAddressDto
                    Group d By PatientAddressDtoGrouped = New PatientAddress With {
                                                              .Address1 = d.Address1,
                                                              .Address2 = d.Address2,
                                                              .City = d.City,
                                                              .State = d.State,
                                                              .Zip = d.Zip
                                                              }
                  Into Group
                  Select New PatientAddress With {
                                                  .Address1 = PatientAddressDtoGrouped.Address1,
                                                  .Address2 = PatientAddressDtoGrouped.Address2,
                                                  .City = PatientAddressDtoGrouped.City,
                                                  .State = PatientAddressDtoGrouped.State,
                                                  .Zip = PatientAddressDtoGrouped.Zip
                                                  }).ToList()

我没有运气就尝试了以下方法：

PatientAddressDto = (From d In PatientAddressDto
                    Select New PatientAddress With {
                                                  .Address1 = d.Address1,
                                                  .Address2 = d.Address2,
                                                  .City = d.City,
                                                  .State = d.State,
                                                  .Zip = d.Zip
                                                    }).Distinct     

并且

PatientAddressDto = PatientAddressDto.GroupBy(Function(p) New PatientAddress With {
                                                  .Address1 = p.Address1,
                                                  .Address2 = p.Address2,
                                                  .City = p.City,
                                                  .State = p.State,
                                                  .Zip = p.Zip
                                                    })

Answer 1

您可以使用anonymous type并使用Key keyword来使相等行为按照您期望的方式运行（C＃不需要）。

通过指定Key前缀来更改分组，并删除PatientAddress用法：

Group d By PatientAddressDtoGrouped = New With {
    Key .Address1 = d.Address1,
    Key .Address2 = d.Address2,
    Key .City = d.City,
    Key .State = d.State,
    Key .Zip = d.Zip
}