使用新文件名继承 StreamWriter

Question

我想编写如下代码：

Public Class LogFile
    Inherits StreamWriter

    Private LogsDirectory As String = Application.StartupPath & "\" & "logs\"

    Public Sub New(shortName As String)            
        Dim fullFilePath As String = LogsDirectory & shortName & "_" & Format(Now, "HHmmss") & ".log"    
        MyBase.New(fullFilePath)
    End Sub

End Class

但是我不得不这样做（因为 Sub New 的第一条语句必须是基本构造函数）：

 Public Class LogFile  
     Inherits StreamWriter       

    Public Sub New(shortName As String)              
        MyBase.New(Application.StartupPath & "\" & "logs\" & shortName & "_" & Format(Now, "HHmmss") & ".log")
    End Sub

End Class

有没有办法'around'这个？在这种情况下没关系，但可以想象，我想做更多的处理，而不适合单行。

Answer 1

只要函数是 Shared 就可以实现你想要的（LogsDirectory 也必须是 Shared）

编译如下：

Public Class LogFile
    Inherits StreamWriter

    Public Sub New(shortName As String)
        MyBase.New(InitFunction(shortName))
    End Sub

    Private Shared LogsDirectory As String = Application.StartupPath & "\" & "logs\"

    Private Shared Function InitFunction(shortname As String) As String
        Dim fullFilePath = LogsDirectory & shortname & "_" & Format(Now, "HHmmss") & ".log"
        Return fullFilePath
    End Function
End Class

使用新文件名继承 StreamWriter

Inheriting StreamWriter with new filename

.net

vb.net

inheritance

streamwriter