Vb.net 我应该在这些示例上实现IDisposable吗

样本1。（如果我的方法之一使用非托管对象）

公共类记录器
'实现IDisposable每个post.run代码分析只问一个问题，它将告诉您应该实现它的类。
Public Class Logger
     'Implements IDisposable <<< is this necessary because of unmanaged object inside the method?

     Public Sub CreateLogFile(ByVal msg As String)
        Try

           If Not String.IsNullOrEmpty(_LogDir) Then
             Try
               Using objWriter As New System.IO.StreamWriter(Format(Now, "MM-dd-yyyy HHmmss") & ".txt", True)
                   objWriter.WriteLine(msg)
                   objWriter.Close()
                End Using
             Catch ex As Exception

             End Try
           End If
        Catch ex As Exception
        End Try
    End Sub

End Class

Public Class frmViewerReport
    'Implements IDisposable <<< is this necessary because of event I added in the winform?

    Public Event DoneAutoPrint()
    Public Event Progress()
    Public Event ProgressDone()
    Public Event ErrorRaised(ByVal msg As String)
End Class

Public Class MyRepository
    'Implements IDisposable <<< is this necessary because of dbcontext?

    Private _ctx As New MyEntities
    Private _User As User
End Class

Public Class MyEntities
    Inherits DbContext
End Class