Public Class time1
    Private h As Integer
    Private m As Integer
    Private s As Integer
    Public Sub New(ByVal myhour As Integer, ByVal myminute As Integer, ByVal mysecond As Integer)
        Me.hour = myhour
        Me.minute = myminute
        Me.second = mysecond
    End Sub
    Public Sub New(ByVal myhour As Integer, ByVal myminute As Integer)
        Me.hour = myhour
        Me.minute = myminute
        Me.second = 0
    End Sub

    Public Property hour() As Integer
        Get
            Return h
        End Get
        Set(ByVal Value As Integer)
            If Value > 23 Or Value < 0 Then
                MessageBox.Show("小時必須在 0~23！")
            Else : h = Value
            End If
        End Set
    End Property
    Public Property minute() As Integer
        Get
            Return m
        End Get
        Set(ByVal Value As Integer)
            If Value > 59 Or Value < 0 Then
                MessageBox.Show("分鐘必須在 0~59！")
            Else : m = Value
            End If
        End Set
    End Property
    Public Property second() As Integer
        Get
            Return s
        End Get
        Set(ByVal Value As Integer)
            If Value > 59 Or Value < 0 Then
                MessageBox.Show("秒必須在 0~59！")
            Else : s = Value
            End If
        End Set
    End Property

    Public Function touniversalstring() As String
        Dim a As String
        If h < 10 Then
            a = "0" & hour() & ":"
        Else : a = hour() & ":"
        End If
        If m < 10 Then
            a = a & "0" & minute & ":"
        Else : a = a & minute & ":"
        End If
        If s < 10 Then
            a = a & "0" & second
        Else : a = a & second
        End If
        Return a
    End Function
End Class