Form1.vb
Public Class TimeTest
Dim time As New Time() ' construct Time with zero arguments
' invoked when user clicks the Add 1 to Second button
Private Sub addSecondButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles addSecondButton.Click
time.Second = (time.Second + 1) Mod 60 ' add 1 to Second
setSecondTextbox.Text = Convert.ToString(time.Second)
' add one minute if 60 seconds have passed
If time.Second = 0 Then
time.Minute = (time.Minute + 1) Mod 60 ' add 1 to Minute
setMinuteTextbox.Text = Convert.ToString(time.Minute)
' add one hour if 60 minutes have passed
If time.Minute = 0 Then
time.Hour = (time.Hour + 1) Mod 24 ' add 1 to Hour
setHourTextbox.Text = Convert.ToString(time.Hour)
End If
End If
UpdateDisplay() ' update the text in output1Label and output2Label
End Sub ' addSecondButton_Click
' handle event when setHourTestox's text changes
Private Sub setHourTextBox_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles setHourTextbox.TextChanged
time.Hour = Convert.ToInt32(setHourTextbox.Text)
UpdateDisplay() ' update the text in output1Label and output2Label
End Sub ' setHourTextBox_TextChanged
' handle event when setMinuteTextBox's text changes
Private Sub setMinuteTextBox_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles setMinuteTextbox.TextChanged
time.Minute = Convert.ToInt32(setMinuteTextbox.Text)
UpdateDisplay() ' update the text in output1Label and output2Label
End Sub ' setMinuteTextBox_TextChanged
' handle event when setSecondTextBoxt's text changed
Private Sub setSecondTextBox_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles setSecondTextbox.TextChanged
time.Second = Convert.ToInt32(setSecondTextbox.Text)
UpdateDisplay() ' update the text in output1Label and output2Label
End Sub ' setSecondTextBox_TextChanged
' update time display
Private Sub UpdateDisplay()
setHourTextbox.Text = Convert.ToString(time.Hour)
setMinuteTextbox.Text = Convert.ToString(time.Minute)
setSecondTextbox.Text = Convert.ToString(time.Second)
output1Label.Text = String.Format("Hour: {0}; Minute: {1}; Second: {2}", time.Hour, time.Minute, time.Second)
output2Label.Text = String.Format("Standard time is: {0}; Universal Time is: {1}", time.ToString(), time.ToUniversalString())
End Sub ' UpdateDisplay
Private Sub output1Label_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles output1Label.Click
End Sub
Private Sub output2Label_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles output2Label.Click
End Sub
Private Sub TimeTest_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
End Class 'TimeTest
Time.vb
Public Class Time
Inherits Object 'if omitted, Object is inherited implicitly
' declare Integer instance variables for the hour, minute and second
Private hourValue As Integer ' 0 - 23
Private minuteValue As Integer ' 0 - 59
Private secondValue As Integer ' 0 - 59
' Time constructor initializes instance variables
' when a Time object is created
Public Sub New()
SetTime(12, 0, 0) ' initialize hour to noon; minute, second to 0
End Sub ' New
' set a new time value using universal time, check validity of the
' data, set invalid hour to noon, set invalid minute, second to zero
Public Sub SetTime(ByVal hh As Integer, ByVal mm As Integer, ByVal ss As Integer)
Hour = hh ' set hour value using Hour property
Minute = mm ' set minute value using Minute property
Second = ss ' set second value using Second property
End Sub ' SetTime
' property Hour
Public Property Hour() As Integer
Get ' return hourValue
Return hourValue
End Get
Set(ByVal value As Integer) ' set hourValue
If (value >= 0 AndAlso value < 24) Then ' in range 0 - 23
hourValue = value ' value is valid
Else ' value is invalid
hourValue = 12 ' set to default of noon
End If
End Set
End Property ' Hour
Public Property Minute() As Integer
Get ' return minuteValue
Return minuteValue
End Get
Set(ByVal value As Integer) ' set minuteValue
If (value >= 0 AndAlso value < 60) Then ' in range 0 - 59
minuteValue = value ' value is valid
Else ' value is invalid
minuteValue = 0 ' set to default of 0
End If
End Set
End Property ' Minute
Public Property Second() As Integer
Get ' return secondValue
Return secondValue
End Get
Set(ByVal value As Integer) ' set secondValue
If (value >= 0 AndAlso value < 60) Then ' in range 0 - 59
secondValue = value ' value is valid
Else ' value is invalid
secondValue = 0 ' set to default of 0
End If
End Set
End Property ' Second
' convert Time to a String in universal-time (24-hour clock) format
Public Function ToUniversalString() As String
Return String.Format("{0}:{1:D2}:{2:D2}", Hour, Minute, Second)
End Function 'ToUniversalString
' convert Time to a String in standard-time (12-hour clock) format
Public Overrides Function ToString() As String
Dim suffix As String ' AM or PM suffix
Dim standardHour As Integer ' a standard hour in the range 1 - 12
' determine whether the 12-hour clock suffix should be AM or PM
If Hour < 12 Then
suffix = "AM"
Else
suffix = "PM"
End If
' convert hour from universal-time format to standard-time format
If (Hour = 12 OrElse Hour = 0) Then
standardHour = 12
Else
standardHour = Hour Mod 12 ' 1 through 11, AM or PM
End If
Return String.Format("{0}:{1:D2}:{2:D2} {3}", standardHour, Minute, Second, suffix)
End Function ' ToString
End Class ' Time
Output
