Public Module Module2

    Public Interface MyInterface

        Property stuName As String

        Function GetScore(ByVal x As Single) As Single

    End Interface

    Public Class StuInfo

        Implements MyInterface

        Private studentScore As Single

        Private studentName As String

        Public Property Score() As Single

            Get

                Return studentScore

            End Get

            Set(ByVal value As Single)

                studentScore = value

            End Set

        End Property

        Public Function GetScore(ByVal x As Single) As Single Implements MyInterface.GetScore

            Return x * 0.8

        End Function

        Public Property StuName() As String Implements MyInterface.stuName

            Get

                Return studentName

            End Get

            Set(ByVal value As String)

                studentName = value

            End Set

        End Property

    End Class

    Public Class StuMessage

        Implements MyInterface

        Private studentName As String

        Private stuScore As Single

        Public Property Score() As Single

            Get

                Return stuScore

            End Get

            Set(ByVal value As Single)

                stuScore = value

            End Set

        End Property

        Public Function GetScore(ByVal x As Single) As Single Implements MyInterface.GetScore

            Return x * 0.8

        End Function

        Public Property StuName() As String Implements MyInterface.stuName

            Get

                Return studentName

            End Get

            Set(ByVal value As String)

                studentName = value

            End Set

        End Property

    End Class

End Module

Public Class TestClassForm

    Public Sub ShowScore(ByVal obj As MyInterface, ByVal s As String, ByVal score As Single)

        MsgBox(s & "成绩为:" & obj.GetScore(score) & "")

    End Sub

    Private Sub TestClassForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

        Dim obj1 As New StuInfo()

        Dim obj2 As New StuMessage()

        ShowScore(obj1, "期中", )

        ShowScore(obj2, "期末", )

    End Sub

End Class