vb.net - 在 vb.Net 中实现继承的泛型接口(interface)

Question

在我们当前的项目中，我使用了一个通用接口(interface) iService，它被所有其他服务接口(interface)继承。例如IService被ILogService继承。

ILogService 接口(interface)然后由 LogService 实现如下:

Public Interface IService(Of T)
    Sub Save(ByVal T As IEntity)
    Sub Remove(ByVal T As IEntity)
    Function FindBy(ByVal Id As Guid) As T
    Function FindAll() As IEnumerable(Of T)
End Interface

Public Interface ILogService
    Inherits IService(Of Log)


    Function FindLogsByOwner(ByVal Owner As Guid, ByVal visibility As LogVisibility) As IList(Of Log)
    Function FindAllLogsByVisibility(ByVal visibility As LogVisibility) As IList(Of Log)
    Function FindAllLogsByType(ByVal type As LogType) As IList(Of Log)

End Interface

Public Class LogService
    Implements ILogService


    Public Function FindAll() As System.Collections.Generic.IEnumerable(Of Model.CSLS.Log) Implements Infrastructure.Domain.IService(Of Model.CSLS.Log).FindAll

    End Function

    Public Function FindBy(Id As System.Guid) As Model.CSLS.Log Implements Infrastructure.Domain.IService(Of Model.CSLS.Log).FindBy

    End Function

    Public Sub Remove(T As Infrastructure.Domain.IEntity) Implements Infrastructure.Domain.IService(Of Model.CSLS.Log).Remove

    End Sub

    Public Sub Save(T As Infrastructure.Domain.IEntity) Implements Infrastructure.Domain.IService(Of Model.CSLS.Log).Save

    End Sub

    Public Function FindAllLogsByType(type As Model.CSLS.LogType) As System.Collections.Generic.IList(Of Model.CSLS.Log) Implements Model.CSLS.ILogService.FindAllLogsByType

    End Function

    Public Function FindAllLogsByVisibility(visibility As Model.CSLS.LogVisibility) As System.Collections.Generic.IList(Of Model.CSLS.Log) Implements Model.CSLS.ILogService.FindAllLogsByVisibility

    End Function

    Public Function FindLogsByOwner(Owner As System.Guid, visibility As Model.CSLS.LogVisibility) As System.Collections.Generic.IList(Of Model.CSLS.Log) Implements Model.CSLS.ILogService.FindLogsByOwner

    End Function
End Class

需要帮助:我试图理解，当我实现 ILogService 接口(interface)时，我仍然在 LogService 类中获得函数/子程序包含:

• IEntity 类型的方法参数 T 而不是 Log

如何更新方法签名以便 T 显示为 Log？

我做错了什么？

Answer 1

你说的是这些吗？

Sub Save(ByVal T As IEntity)
Sub Remove(ByVal T As IEntity)

这很令人困惑，因为在上面的方法中，T 是方法参数的名称，不是泛型类型参数。它可以很容易地成为 foo 或 bar。在每种情况下，T 的类型都是 IEntity。

如果此处的意图是Save 和Remove 应该各自接受一个T 类型的参数，但是该类型 T 必须实现 IEntity，这就是您要表达的方式:

Public Interface IService(Of T As IEntity)
    Sub Save(ByVal entity As T)
    Sub Remove(ByVal entity As T)
    Function FindBy(ByVal Id As Guid) As T
    Function FindAll() As IEnumerable(Of T)
End Interface